FreeBSD 13-GENERIC-CURRENT tunables

sysctl-tunables

kern.maxproc: Maximum number of processes
kern.ngroups: Maximum number of supplemental groups a user can belong to
kern.ipc.shm_allow_removed: Enable/Disable attachment to attached segments marked for removal
kern.ipc.shm_use_phys: Enable/Disable locking of shared memory pages in core
kern.ipc.shmall: Maximum number of pages available for shared memory
kern.ipc.shmseg: Number of segments per process
kern.ipc.shmmni: Number of shared memory identifiers
kern.ipc.shmmin: Minimum shared memory segment size
kern.ipc.shmmax: Maximum shared memory segment size
kern.ipc.semaem: Adjust on exit max value
kern.ipc.semvmx: Semaphore maximum value
kern.ipc.semusz: Size in bytes of undo structure
kern.ipc.semume: Max undo entries per process
kern.ipc.semopm: Max operations per semop call
kern.ipc.semmsl: Max semaphores per id
kern.ipc.semmnu: Maximum number of undo structures in the system
kern.ipc.semmns: Maximum number of semaphores in the system
kern.ipc.semmni: Number of semaphore identifiers
kern.ipc.msgseg: Number of message segments
kern.ipc.msgssz: Size of a message segment
kern.ipc.msgtql: Maximum number of messages in the system
kern.ipc.msgmnb: Maximum number of bytes in a queue
kern.ipc.msgmni: Number of message queue identifiers
kern.ipc.maxpipekva: Pipe KVA limit
kern.ipc.umtx_max_robust: 
kern.ipc.umtx_vnode_persistent: False forces destruction of umtx attached to file, on last close
kern.ipc.maxmbufmem: Maximum real memory allocatable to various mbuf types
kern.crypto_workers_num: Number of crypto workers used to dispatch crypto jobs
kern.tty_info_kstacks: Enable printing kernel stack(9) traces on ^T (tty info)
kern.tty_drainwait: Default output drain timeout in seconds
kern.trap_enotcap: Deliver SIGTRAP on ENOTCAPABLE
kern.smp.topology: Topology override setting; 0 is default provided by hardware.
kern.smp.disabled: SMP has been disabled from the loader
kern.always_console_output: Always output to console despite TIOCCONS
kern.log_console_add_linefeed: log_console() adds extra newlines
kern.log_console_output: Duplicate console output to the syslog
kern.boot_tag: Tag added to dmesg at start of boot
kern.sgrowsiz: Amount to grow stack on a stack fault
kern.maxssiz: Maximum stack size
kern.dflssiz: Initial stack size limit
kern.maxdsiz: Maximum data size
kern.dfldsiz: Initial data size limit
kern.maxtsiz: Maximum text size
kern.bio_transient_maxcnt: Maximum number of transient BIOs mappings
kern.maxbcache: Maximum value of vfs.maxbufspace
kern.maxswzone: Maximum memory for swap metadata
kern.msgbufsize: Size of the kernel message buffer
kern.nswbuf: Number of swap buffers
kern.nbuf: Number of buffers in the buffer cache
kern.hz: Number of clock ticks per second
kern.msgbuf_show_timestamp: Show timestamp in msgbuf
kern.pin_pcpu_swi: Pin the per-CPU swis (except PCPU 0, which is also default
kern.pin_default_swi: Pin the default (non-per-cpu) swi (shared with PCPU 0 swi)
kern.ncallout: Number of entries in callwheel and size of timeout() preallocation
kern.timecounter.tsc_shift: Shift to pre-apply for the maximum TSC frequency
kern.timecounter.smp_tsc_adjust: Try to adjust TSC on APs to match BSP
kern.timecounter.smp_tsc: Indicates whether the TSC is safe to use in SMP mode
kern.timecounter.invariant_tsc: Indicates whether the TSC is P-state invariant
kern.timecounter.alloweddeviation: Allowed time interval deviation in percents
kern.compress_user_cores_level: Corefile compression level
kern.compress_user_cores: Enable compression of user corefiles (1 = gzip, 2 = zstd)
kern.capmode_coredump: Allow processes in capability mode to dump core
kern.sugid_coredump: Allow setuid and setgid processes to dump core
kern.lognosys: Log invalid syscalls
kern.sigqueue.preallocate: Preallocated signal memory size
kern.kerneldump_gzlevel: Kernel crash dump compression level
kern.powercycle_on_panic: Do a power cycle instead of a reboot on a panic
kern.poweroff_on_panic: Do a power off instead of a reboot on a panic
kern.sync_on_panic: Do a sync before rebooting from a panic
kern.panic_reboot_wait_time: Seconds to wait before rebooting after a panic
kern.racct.rctl.throttle_pct2: Throttling penalty for container consumption, in percent
kern.racct.rctl.throttle_pct: Throttling penalty for process consumption, in percent
kern.racct.rctl.throttle_max: Longest throttling duration, in hz
kern.racct.rctl.throttle_min: Shortest throttling duration, in hz
kern.racct.rctl.devctl_rate_limit: Maximum number of devctl messages per second
kern.racct.rctl.maxbufsize: Maximum output buffer size
kern.racct.enable: Enable RACCT/RCTL
kern.hwpmc.softevents: maximum number of soft events
kern.pid_max: Maximum allowed pid
kern.maxusers: Hint for kernel tuning
kern.module_path: module load search path
kern.ktrace.genio_size: Maximum size of genio event payload
kern.coredump_pack_vmmapinfo: Enable file path packing in 'procstat -v' coredump notes
kern.coredump_pack_fileinfo: Enable file path packing in 'procstat -f' coredump notes
kern.eventtimer.idletick: Run periodic events when idle
kern.eventtimer.singlemul: Multiplier for periodic mode
kern.vty: Console vty driver
kern.elf32.fallback_brand: ELF32 brand of last resort
kern.elf64.fallback_brand: ELF64 brand of last resort
kern.geom.raid.raid5.enable: Enable RAID5 transformation module taste
kern.geom.raid.raid1e.enable: Enable RAID1E transformation module taste
kern.geom.raid.raid1e.rebuild_meta_update: When to update the meta data.
kern.geom.raid.raid1e.rebuild_cluster_idle: Number of slabs to do each time we trigger a rebuild cycle
kern.geom.raid.raid1e.rebuild_fair_io: Fraction of the I/O bandwidth to use when disk busy for rebuild.
kern.geom.raid.raid1e.rebuild_slab_size: Amount of the disk to rebuild each read/write cycle of the rebuild.
kern.geom.raid.raid1.enable: Enable RAID1 transformation module taste
kern.geom.raid.raid1.rebuild_meta_update: When to update the meta data.
kern.geom.raid.raid1.rebuild_cluster_idle: Number of slabs to do each time we trigger a rebuild cycle
kern.geom.raid.raid1.rebuild_fair_io: Fraction of the I/O bandwidth to use when disk busy for rebuild.
kern.geom.raid.raid1.rebuild_slab_size: Amount of the disk to rebuild each read/write cycle of the rebuild.
kern.geom.raid.raid0.enable: Enable RAID0 transformation module taste
kern.geom.raid.concat.enable: Enable CONCAT transformation module taste
kern.geom.raid.sii.enable: Enable SiI metadata format taste
kern.geom.raid.promise.enable: Enable Promise metadata format taste
kern.geom.raid.nvidia.enable: Enable NVIDIA metadata format taste
kern.geom.raid.jmicron.enable: Enable JMicron metadata format taste
kern.geom.raid.intel.enable: Enable Intel metadata format taste
kern.geom.raid.ddf.enable: Enable DDF metadata format taste
kern.geom.raid.idle_threshold: Time in microseconds to consider a volume idle.
kern.geom.raid.name_format: Providers name format.
kern.geom.raid.disconnect_on_failure: Disconnect component on I/O failure.
kern.geom.raid.clean_time: Mark volume as clean when idling
kern.geom.raid.start_timeout: Time to wait for all array components
kern.geom.raid.read_err_thresh: Number of read errors equated to disk failure
kern.geom.raid.debug: Debug level
kern.geom.raid.aggressive_spare: Use disks without metadata as spare
kern.geom.raid.enable: Enable on-disk metadata taste
kern.geom.part.mbr.enforce_chs: Enforce alignment to CHS addressing
kern.geom.part.auto_resize: Enable auto resize
kern.geom.part.check_integrity: Enable integrity checking
kern.geom.label.disk_ident.enable: Create device nodes for drives which export a disk identification string
kern.geom.label.gptid.enable: Create device nodes for GPT UUIDs
kern.geom.label.gpt.enable: Create device nodes for GPT labels
kern.geom.label.ufs.enable: Create device nodes for UFS volume names
kern.geom.label.ufsid.enable: Create device nodes for UFS file system IDs
kern.geom.label.reiserfs.enable: Create device nodes for REISERFS volumes
kern.geom.label.ntfs.enable: Create device nodes for NTFS volumes
kern.geom.label.msdosfs.enable: Create device nodes for MSDOSFS volumes
kern.geom.label.iso9660.enable: Create device nodes for ISO9660 volume names
kern.geom.label.ext2fs.enable: Create device nodes for EXT2FS volumes
kern.geom.label.debug: Debug level
kern.geom.debugflags: Set various trace levels for GEOM debugging
kern.geom.disk.da0.led: LED name
kern.geom.disk.mmcsd0.led: LED name
kern.geom.disk.cd0.led: LED name
kern.geom.disk.ada0.led: LED name
kern.vt.splash_cpu_duration: Hide logos after (seconds)
kern.vt.splash_cpu_style: Draw logo style (0 = Alternate beastie, 1 = Beastie, 2 = Orb)
kern.vt.splash_ncpu: Override number of logos displayed (0 = do not override)
kern.vt.splash_cpu: Show logo CPUs during boot
kern.vt.kbd_panic: Enable request to panic.  See kbdmap(5) to configure.
kern.vt.kbd_debug: Enable key combination to enter debugger.  See kbdmap(5) to configure (typically Ctrl-Alt-Esc).
kern.vt.kbd_reboot: Enable reboot keyboard combination.  See kbdmap(5) to configure (typically Ctrl-Alt-Delete).
kern.vt.kbd_poweroff: Enable Power Off keyboard combination.  See kbdmap(5) to configure.
kern.vt.kbd_halt: Enable halt keyboard combination.  See kbdmap(5) to configure.
kern.vt.suspendswitch: Switch to VT0 before suspend
kern.vt.deadtimer: Time to wait busy process in VT_PROCESS mode
kern.vt.debug: vt(9) debug level
kern.vt.enable_bell: Enable bell
kern.vt.enable_altgr: Enable AltGr key (Do not assume R.Alt as Alt)
kern.random.fortuna.minpoolsize: Minimum pool size necessary to cause a reseed
kern.cam.enc.emulate_array_devices: Emulate Array Devices for SAF-TE
kern.cam.sa.allow_io_split: Default I/O split value
kern.cam.da.0.delete_method: BIO_DELETE execution method
kern.cam.da.disable_wp_detection: Disable detection of write-protected disks
kern.cam.da.send_ordered: Send Ordered Tags
kern.cam.da.default_timeout: Normal I/O timeout (in seconds)
kern.cam.da.retry_count: Normal I/O retry count
kern.cam.da.poll_period: Media polling period in seconds
kern.cam.ada.write_cache: Enable disk write cache
kern.cam.ada.read_ahead: Enable disk read-ahead
kern.cam.ada.spindown_suspend: Spin down upon suspend
kern.cam.ada.spindown_shutdown: Spin down upon shutdown
kern.cam.ada.send_ordered: Send Ordered Tags
kern.cam.ada.default_timeout: Normal I/O timeout (in seconds)
kern.cam.ada.retry_count: Normal I/O retry count
kern.cam.cd.timeout: Timeout, in us, for read operations
kern.cam.cd.retry_count: Normal I/O retry count
kern.cam.cd.poll_period: Media polling period in seconds
kern.cam.cam_srch_hi: allow search above LUN 7 for SCSI3 and greater devices
kern.cam.nda.max_trim: Maximum number of BIO_DELETE to send down as a DSM TRIM.
kern.cam.pmp.hide_special: Hide extra ports
kern.cam.pmp.default_timeout: Normal I/O timeout (in seconds)
kern.cam.pmp.retry_count: Normal I/O retry count
kern.cam.debug_delay: Delay in us after each debug message
kern.cam.dflags: Enabled debug flags
kern.cam.num_doneqs: Number of completion queues/threads
kern.cam.announce_nosbuf: Don't use sbuf for announcements
kern.cam.boot_delay: Bus registration wait time
kern.cam.sort_io_queues: Sort IO queues to try and optimise disk access patterns
vm.pmap.pti: Page Table Isolation enabled
vm.pmap.pcid_enabled: Is TLB Context ID enabled ?
vm.pmap.pg_ps_enabled: Are large page mappings enabled?
vm.background_launder_max: background laundering cap, in kilobytes
vm.background_launder_rate: background laundering rate, in kilobytes per second
vm.act_scan_laundry_weight: weight given to clean vs. dirty pages in active queue scans
vm.pageout_oom_seq: back-to-back calls to oom detector to start OOM
vm.disable_swapspace_pageouts: Disallow swapout of dirty pages
vm.lowmem_period: Low memory callback period
vm.pageout_update_period: Maximum active LRU update period
vm.panic_on_oom: panic on out of memory instead of killing the largest process
vm.boot_pages: number of pages allocated for bootstrapping the VM system
vm.mincore_mapped: mincore reports mappings, not residency
vm.old_mlock: Do not apply RLIMIT_MEMLOCK on mlockall
vm.zone_warnings: Warn when UMA zones becomes full
vm.debug.divisor: Debug & thrash every this item in memory allocator
vm.phys_pager_cluster: prefault window size for phys pager
vm.kmem_size_scale: Scale factor for kernel memory size
vm.kmem_size_max: Maximum size of kernel memory
vm.kmem_size_min: Minimum size of kernel memory
vm.kmem_zmax: Maximum allocation size that malloc(9) would use UMA as backend
vm.kmem_size: Size of kernel memory
vfs.msdosfs.use_buf_pager: Use buffer pager instead of bmap
vfs.nfs.use_buf_pager: Use buffer pager instead of direct readrpc call
vfs.nfs.fileid_maxwarnings: Limit fileid corruption warnings; 0 is off; -1 is unlimited
vfs.nfs.userhashsize: Size of hash tables for uid/name mapping
vfs.cd9660.use_buf_pager: Use buffer pager instead of bmap
vfs.autofs.interruptible: Allow requests to be interrupted by signal
vfs.autofs.retry_delay: Number of seconds before retrying
vfs.autofs.retry_attempts: Number of attempts before failing mount
vfs.autofs.cache: Number of seconds to wait before reinvoking automountd(8) for any given file or directory
vfs.autofs.timeout: Number of seconds to wait for automountd(8)
vfs.autofs.mount_on_stat: Trigger mount on stat(2) on mountpoint
vfs.autofs.debug: Enable debug messages
vfs.zfs.trim.max_interval: Maximum interval between TRIM queue processing (seconds)
vfs.zfs.trim.timeout: Delay TRIMs by up to this many seconds
vfs.zfs.trim.txg_delay: Delay TRIMs by up to this many TXGs
vfs.zfs.trim.enabled: Enable ZFS TRIM
vfs.zfs.vol.immediate_write_sz: Minimal size for indirect log write
vfs.zfs.vol.unmap_sync_enabled: UNMAPs requested as sync are executed synchronously
vfs.zfs.vol.unmap_enabled: Enable UNMAP functionality
vfs.zfs.vol.recursive: Allow zpools to use zvols as vdevs (DANGEROUS)
vfs.zfs.vol.mode: Expose as GEOM providers (1), device files (2) or neither
vfs.zfs.debug: Debug level
vfs.zfs.immediate_write_sz: Minimal size for indirect log write
vfs.zfs.sync_pass_rewrite: rewrite new bps starting in this pass
vfs.zfs.sync_pass_dont_compress: don't compress starting in this pass
vfs.zfs.sync_pass_deferred_free: defer frees starting in this pass
vfs.zfs.zio.dva_throttle_enabled: Enable allocation throttling
vfs.zfs.zio.exclude_metadata: Exclude metadata buffers from dumps as well
vfs.zfs.zio.use_uma: Use uma(9) for ZIO allocations
vfs.zfs.zil_slog_bulk: Maximal SLOG commit size with sync priority
vfs.zfs.cache_flush_disable: Disable cache flush
vfs.zfs.zil_replay_disable: Disable intent logging replay
vfs.zfs.standard_sm_blksz: Block size for standard space map.  Power of 2 and greater than 4096.
vfs.zfs.dtl_sm_blksz: Block size for DTL space map.  Power of 2 and greater than 4096.
vfs.zfs.vdev.trim_max_pending: Maximum pending TRIM segments for a vdev
vfs.zfs.vdev.bio_delete_disable: Disable BIO_DELETE
vfs.zfs.vdev.bio_flush_disable: Disable BIO_FLUSH
vfs.zfs.vdev.def_queue_depth: Default queue depth for each allocator
vfs.zfs.vdev.queue_depth_pct: Queue depth percentage for each top-level
vfs.zfs.vdev.write_gap_limit: Acceptable gap between two writes being aggregated
vfs.zfs.vdev.read_gap_limit: Acceptable gap between two reads being aggregated
vfs.zfs.vdev.aggregation_limit: I/O requests are aggregated up to this size
vfs.zfs.vdev.initializing_max_active: Maximum number of I/O requests of type initializing active for each device
vfs.zfs.vdev.initializing_min_active: Initial number of I/O requests of type initializing active for each device
vfs.zfs.vdev.removal_max_active: Maximum number of I/O requests of type removal active for each device
vfs.zfs.vdev.removal_min_active: Initial number of I/O requests of type removal active for each device
vfs.zfs.vdev.trim_max_active: Maximum number of I/O requests of type trim active for each device
vfs.zfs.vdev.trim_min_active: Initial number of I/O requests of type trim active for each device
vfs.zfs.vdev.scrub_max_active: Maximum number of I/O requests of type scrub active for each device
vfs.zfs.vdev.scrub_min_active: Initial number of I/O requests of type scrub active for each device
vfs.zfs.vdev.async_write_max_active: Maximum number of I/O requests of type async_write active for each device
vfs.zfs.vdev.async_write_min_active: Initial number of I/O requests of type async_write active for each device
vfs.zfs.vdev.async_read_max_active: Maximum number of I/O requests of type async_read active for each device
vfs.zfs.vdev.async_read_min_active: Initial number of I/O requests of type async_read active for each device
vfs.zfs.vdev.sync_write_max_active: Maximum number of I/O requests of type sync_write active for each device
vfs.zfs.vdev.sync_write_min_active: Initial number of I/O requests of type sync_write active for each device
vfs.zfs.vdev.sync_read_max_active: Maximum number of I/O requests of type sync_read active for each device
vfs.zfs.vdev.sync_read_min_active: Initial number of I/O requests of type sync_read active for each device
vfs.zfs.vdev.max_active: The maximum number of I/Os of all types active for each device.
vfs.zfs.vdev.async_write_active_max_dirty_percent: Percentage of async write dirty data above which async_write_max_active is used.
vfs.zfs.vdev.async_write_active_min_dirty_percent: Percentage of async write dirty data below which async_write_min_active is used.
vfs.zfs.vdev.mirror.non_rotating_seek_inc: Non-rotating media load increment for seeking I/O's
vfs.zfs.vdev.mirror.non_rotating_inc: Non-rotating media load increment for non-seeking I/O's
vfs.zfs.vdev.mirror.rotating_seek_offset: Offset in bytes from the last I/O which triggers a reduced rotating media seek increment
vfs.zfs.vdev.mirror.rotating_seek_inc: Rotating media load increment for seeking I/O's
vfs.zfs.vdev.mirror.rotating_inc: Rotating media load increment for non-seeking I/O's
vfs.zfs.vdev.cache.bshift: Turn too small requests into 1 << this value
vfs.zfs.vdev.cache.size: Size of VDEV cache
vfs.zfs.vdev.cache.max: Maximum I/O request size that increase read size
vfs.zfs.vdev.default_ms_shift: Shift between vdev size and number of metaslabs
vfs.zfs.vdev.min_ms_count: Minimum number of metaslabs per top-level vdev
vfs.zfs.vdev.max_ms_count: Maximum number of metaslabs per top-level vdev
vfs.zfs.txg.timeout: Maximum seconds worth of delta per txg
vfs.zfs.space_map_ibs: Space map indirect block shift
vfs.zfs.spa_allocators: Number of allocators per metaslab group
vfs.zfs.spa_min_slop: Minimal value of reserved space
vfs.zfs.spa_slop_shift: Shift value of reserved space (1/(2^spa_slop_shift)).
vfs.zfs.spa_asize_inflation: Worst case inflation factor for single sector writes
vfs.zfs.deadman_enabled: Kernel panic on stalled ZFS I/O
vfs.zfs.deadman_checktime_ms: Period of checks for stalled ZFS I/O in milliseconds
vfs.zfs.deadman_synctime_ms: Stalled ZFS I/O expiration time in milliseconds
vfs.zfs.debugflags: Debug flags for ZFS testing.
vfs.zfs.recover: Try to recover from otherwise-fatal errors.
vfs.zfs.spa_load_verify_data: Check user data on import?
vfs.zfs.spa_load_verify_metadata: Check metadata on import?
vfs.zfs.spa_load_verify_maxinflight: Maximum number of concurrent scrub I/Os to create while verifying a pool while importing it
vfs.zfs.max_missing_tvds_scan: allow importing pools with missing top-level vdevs during scan
vfs.zfs.max_missing_tvds_cachefile: allow importing pools with missing top-level vdevs in cache file
vfs.zfs.max_missing_tvds: allow importing pools with missing top-level vdevs
vfs.zfs.spa_load_print_vdev_tree: print out vdev tree during pool import
vfs.zfs.check_hostid: Check hostid on import?
vfs.zfs.reference_tracking_enable: Track reference holders to refcount_t objects, used mostly by ZFS
vfs.zfs.mg_fragmentation_threshold: Percentage of metaslab group size that should be considered eligible for allocations unless all metaslab groups within the metaslab class have also crossed this threshold
vfs.zfs.mg_noalloc_threshold: Percentage of metaslab group size that should be free to make it eligible for allocation
vfs.zfs.condense_pct: Condense on-disk spacemap when it is more than this many percents of in-memory counterpart
vfs.zfs.metaslab_sm_blksz: Block size for metaslab DTL space map.  Power of 2 and greater than 4096.
vfs.zfs.metaslab.bias_enabled: Enable metaslab group biasing
vfs.zfs.metaslab.lba_weighting_enabled: Enable LBA weighting (i.e. outer tracks are given preference)
vfs.zfs.metaslab.fragmentation_factor_enabled: Enable fragmentation weighting on metaslabs
vfs.zfs.metaslab.preload_enabled: Max number of metaslabs per group to preload
vfs.zfs.metaslab.preload_limit: Max number of metaslabs per group to preload
vfs.zfs.metaslab.unload_delay: Number of TXGs that an unused metaslab can be kept in memory
vfs.zfs.metaslab.load_pct: Percentage of cpus that can be used by the metaslab taskq
vfs.zfs.metaslab.min_alloc_size: A metaslab is considered "free" if it contains a contiguous segment which is greater than vfs.zfs.metaslab.min_alloc_size
vfs.zfs.metaslab.df_free_pct: The minimum free space, in percent, which must be available in a space map to continue allocations in a first-fit fashion
vfs.zfs.metaslab.df_alloc_threshold: Minimum size which forces the dynamic allocator to change it's allocation strategy
vfs.zfs.metaslab.debug_unload: Prevent metaslabs from being unloaded
vfs.zfs.metaslab.debug_load: Load all metaslabs when pool is first opened
vfs.zfs.metaslab.fragmentation_threshold: Maximum percentage of metaslab fragmentation level to keep their active state
vfs.zfs.metaslab.force_ganging: Force gang block allocation for blocks larger than or equal to this value
vfs.zfs.free_bpobj_enabled: Enable free_bpobj processing
vfs.zfs.free_max_blocks: Maximum number of blocks to free in one TXG
vfs.zfs.zfs_scan_checkpoint_interval: Scan progress on-disk checkpointing interval
vfs.zfs.zfs_scan_legacy: Scrub using legacy non-sequential method
vfs.zfs.no_scrub_prefetch: Disable scrub prefetching
vfs.zfs.no_scrub_io: Disable scrub I/O
vfs.zfs.resilver_min_time_ms: Min millisecs to resilver per txg
vfs.zfs.free_min_time_ms: Min millisecs to free per txg
vfs.zfs.scan_min_time_ms: Min millisecs to scrub per txg
vfs.zfs.scan_idle: Idle scan window in clock ticks
vfs.zfs.scrub_delay: Number of ticks to delay scrub
vfs.zfs.resilver_delay: Number of ticks to delay resilver
vfs.zfs.top_maxinflight: Maximum I/Os per top-level vdev
vfs.zfs.zfetch.array_rd_sz: Number of bytes in a array_read at which we stop prefetching
vfs.zfs.zfetch.max_idistance: Max bytes to prefetch indirects for per stream
vfs.zfs.zfetch.max_distance: Max bytes to prefetch per stream
vfs.zfs.zfetch.min_sec_reap: Min time before stream reclaim
vfs.zfs.zfetch.max_streams: Max # of streams per zfetch
vfs.zfs.dirty_data_sync: Force a txg if the number of dirty buffer bytes exceed this value
vfs.zfs.dirty_data_max_percent: The percent of physical memory used to auto calculate dirty_data_max
vfs.zfs.dirty_data_max_max: The absolute cap on dirty_data_max when auto calculating
vfs.zfs.dirty_data_max: The maximum amount of dirty data in bytes after which new writes are halted until space becomes available
vfs.zfs.max_recordsize: Maximum block size.  Expect dragons when tuning this.
vfs.zfs.default_ibs: Default dnode indirect block shift
vfs.zfs.default_bs: Default dnode block shift
vfs.zfs.send_holes_without_birth_time: Send holes without birth time
vfs.zfs.mdcomp_disable: Disable metadata compression
vfs.zfs.per_txg_dirty_frees_percent: Percentage of dirtied blocks from frees in one txg
vfs.zfs.nopwrite_enabled: Enable nopwrite feature
vfs.zfs.dedup.prefetch: Enable/disable prefetching of dedup-ed blocks which are going to be freed
vfs.zfs.dbuf_cache_lowater_pct: max percents below the dbuf cache size
vfs.zfs.dbuf_cache_hiwater_pct: max percents above the dbuf cache size
vfs.zfs.dbuf_metadata_cache_shift: dbuf metadata cache size as log2 fraction of ARC
vfs.zfs.dbuf_cache_shift: dbuf cache size as log2 fraction of ARC
vfs.zfs.dbuf_metadata_cache_max_bytes: dbuf metadata cache size in bytes
vfs.zfs.dbuf_cache_max_bytes: dbuf cache size in bytes
vfs.zfs.arc_meta_strategy: ARC metadata reclamation strategy (0 = metadata only, 1 = balance data and metadata)
vfs.zfs.arc_kmem_cache_reap_retry_ms: Interval between ARC kmem_cache reapings
vfs.zfs.compressed_arc_enabled: Enable compressed ARC
vfs.zfs.arc_average_blocksize: ARC average blocksize
vfs.zfs.arc_no_grow_shift: log2(fraction of ARC which must be free to allow growing)
vfs.zfs.arc_min: Minimum ARC size
vfs.zfs.arc_max: Maximum ARC size
vfs.zfs.abd_chunk_size: The size of the chunks ABD allocates
vfs.zfs.abd_scatter_enabled: Enable scattered ARC data buffers
vfs.ffs.use_buf_pager: Always use buffer pager instead of bmap
vfs.ffs.doasyncinodeinit: Perform inode block initialization using asynchronous writes
vfs.ffs.dotrimcons: enable BIO_DELETE / TRIM consolidation
vfs.root_mount_always_wait: Wait for root mount holds even if the root device already exists
vfs.lookup_cap_dotdot_nonlocal: enables ".." components in path lookup in capability mode on non-local mount
vfs.lookup_cap_dotdot: enables ".." components in path lookup in capability mode
vfs.typenumhash: Set vfc_typenum using a hash calculation on vfc_name, so that it does notchange when file systems are loaded in a different order.
vfs.buf_pager_relbuf: Make buffer pager release buffers after reading
vfs.maxbcachebuf: Maximum size of a buffer cache block
vfs.nfsd.fha.max_reqs_per_nfsd: Maximum requests that single nfsd thread should be working on at any time
vfs.nfsd.fha.max_nfsds_per_fh: Maximum nfsd threads that should be working on requests for the same file handle
vfs.nfsd.fha.bin_shift: Maximum locality distance 2^(bin_shift) bytes
vfs.nfsd.fha.write: Enable NFS FHA write locality
vfs.nfsd.fha.read: Enable NFS FHA read locality
vfs.nfsd.fha.enable: Enable NFS File Handle Affinity (FHA)
vfs.nfsd.server_max_nfsvers: The highest version of NFS handled by the server
vfs.nfsd.server_min_nfsvers: The lowest version of NFS handled by the server
vfs.nfsd.nfs_privport: Only allow clients using a privileged port for NFSv2, 3 and 4
vfs.nfsd.v4statelimit: High water limit for NFSv4 opens+locks+delegations
vfs.nfsd.layouthighwater: High water mark for number of layouts set via loader.conf
vfs.nfsd.sessionhashsize: Size of session hash table set via loader.conf
vfs.nfsd.fhhashsize: Size of file handle hash table set via loader.conf
vfs.nfsd.clienthashsize: Size of client hash table set via loader.conf
vfs.nfsd.statehashsize: Size of state hash table set via loader.conf
net.inet.ip.fw.default_to_accept: Make the default rule accept all packets.
net.inet.ip.mcast.loop: Loopback multicast datagrams by default
net.inet.ip.mcast.maxsocksrc: Max source filters per socket
net.inet.ip.mcast.maxgrpsrc: Max source filters per group
net.inet.tcp.syncache.hashsize: Size of TCP syncache hashtable
net.inet.tcp.syncache.cachelimit: Overall entry limit for syncache
net.inet.tcp.syncache.bucketlimit: Per-bucket hash limit for syncache
net.inet.tcp.soreceive_stream: Using soreceive_stream for TCP sockets
net.inet.tcp.tcbhashsize: Size of TCP control-block hashtable
net.inet.tcp.reass.queueguard: Number of TCP Segments in Reassembly Queue where we flip over to guard mode
net.inet.tcp.reass.new_limit: Do we use the new limit method we are discussing?
net.inet.tcp.reass.maxqueuelen: Maximum number of TCP Segments per Reassembly Queue
net.inet.tcp.reass.maxsegments: Global maximum number of TCP Segments in Reassembly Queue
net.inet.tcp.lro.entries: default number of LRO entries
net.inet.tcp.hostcache.bucketlimit: Per-bucket hash limit for hostcache
net.inet.tcp.hostcache.hashsize: Size of TCP hostcache hashtable
net.inet.tcp.hostcache.cachelimit: Overall entry limit for hostcache
net.inet.tcp.fastopen.ccache_buckets: Client cookie cache number of buckets (power of 2)
net.inet.tcp.fastopen.ccache_bucket_limit: Max entries per bucket in client cookie cache
net.link.bridge.inherit_mac: Inherit MAC address from the first bridge member
net.link.bridge.log_stp: Log STP state changes
net.link.bridge.pfil_local_phys: Packet filter on the physical interface for locally destined packets
net.link.bridge.pfil_member: Packet filter on the member interface
net.link.bridge.ipfw_arp: Filter ARP packets through IPFW layer2
net.link.bridge.pfil_bridge: Packet filter on the bridge interface
net.link.bridge.pfil_onlyip: Only pass IP packets when pfil is enabled
net.link.tap.devfs_cloning: Enable legacy devfs interface creation
net.link.tun.devfs_cloning: Enable legacy devfs interface creation.
net.link.log_promisc_mode_change: log promiscuous mode change events
net.link.ifqmaxlen: max send queue size
net.key.spdcache.threshold: Number of SPs that make the SPD cache active
net.key.spdcache.maxentries: Maximum number of entries in the SPD cache (power of 2, 0 to disable)
net.inet6.ip6.mcast.loop: Loopback multicast datagrams by default
net.inet6.ip6.mcast.maxsocksrc: Max source filters per socket
net.inet6.ip6.mcast.maxgrpsrc: Max source filters per group
net.inet6.mld.use_allow: Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves
net.inet6.mld.v2enable: Enable MLDv2
net.inet6.mld.v1enable: Enable fallback to MLDv1
net.graph.maxdata: Maximum number of data queue items to allocate
net.graph.maxalloc: Maximum number of non-data queue items to allocate
net.graph.threads: Number of queue processing threads
net.netdump.arp_retries: Number of ARP attempts before giving up
net.netdump.retries: Number of retransmit attempts before giving up
net.netdump.polls: Number of times to poll before assuming packet loss (0.5ms per poll)
net.netdump.debug: Debug message verbosity
net.add_addr_allfibs: 
net.fibs: 
net.isr.defaultqlimit: Default netisr per-protocol, per-CPU queue limit if not set by protocol
net.isr.maxqlimit: Maximum netisr per-protocol, per-CPU queue depth.
net.isr.bindthreads: Bind netisr threads to CPUs.
net.isr.maxthreads: Use at most this many CPUs for netisr processing
net.isr.dispatch: netisr dispatch policy
debug.minidump: Enable mini crash dumps
debug.hwpstate_verify: Verify P-state after setting
debug.hwpstate_verbose: Debug hwpstate
debug.x86bios.int: Trace software interrupt handlers
debug.x86bios.call: Trace far function calls
debug.vesa.shadow_rom: Enable video BIOS shadow
debug.psm.loglevel: Verbosity level
debug.witness.output_channel: Output channel for warnings
debug.witness.witness_count: 
debug.witness.skipspin: 
debug.witness.trace: 
debug.witness.kdb: 
debug.witness.watch: witness is watching lock operations
debug.clock_show_io: Enable debug printing of RTC clock I/O; 1=reads, 2=writes, 3=both.
debug.rman_debug: rman debug
debug.kdb.alt_break_to_debugger: Enable alternative break to debugger
debug.kdb.break_to_debugger: Enable break to debugger
debug.clocktime: Enable printing of clocktime debugging
debug.obsolete_panic: Bus debug level
debug.umtx.robust_faults_verbose: 
debug.allow_insane_settime: do not perform possibly restrictive checks on settime(2) args
debug.kassert.suppress_in_panic: KASSERTs will be suppressed while handling a panic
debug.kassert.log_mute_at: max number of KASSERTS to log
debug.kassert.log_pps_limit: limit number of log messages per second
debug.kassert.log_panic_at: max number of KASSERTS before we will panic
debug.kassert.warnings: number of KASSERTs that have been triggered
debug.kassert.do_log: If warn_only is enabled, log (1) or do not log (0) assertion violations
debug.kassert.do_kdb: KASSERT will enter the debugger
debug.kassert.warn_only: KASSERT triggers a panic (0) or just a warning (1)
debug.trace_all_panics: Print stack traces on secondary kernel panics
debug.trace_on_panic: Print stack trace on kernel panic
debug.debugger_on_trap: Run debugger on kernel trap before panic
debug.debugger_on_panic: Run debugger on kernel panic
debug.osd: OSD debug level
debug.malloc.zone_offset: Separate malloc types by examining the Nth character in the malloc type short description.
debug.malloc.numzones: Number of malloc uma subzones
debug.cpufreq.verbose: Print verbose debugging messages
debug.cpufreq.lowest: Don't provide levels below this frequency.
debug.gdbcons: copy console messages to GDB
debug.uart_force_poll: Force UART polling
debug.uart_poll_freq: UART poll frequency
debug.acpi.resume_beep: Beep the PC speaker when resuming
debug.acpi.ec.timeout: Total time spent waiting for a response (poll+sleep)
debug.acpi.ec.polled: Force use of polled mode (only if interrupt mode doesn't work)
debug.acpi.ec.burst: Enable use of burst mode (faster for nearly all systems)
debug.acpi.cpu_unordered: Do not use the MADT to match ACPI Processor objects to CPUs.
debug.acpi.default_register_width: Ignore register widths set by FADT
debug.acpi.interpreter_slack: Turn on interpreter slack mode.
debug.acpi.max_threads: Maximum acpi threads
debug.acpi.max_tasks: Maximum acpi tasks
hw.vmm.amdvi.disable_io_fault: 
hw.vmm.amdvi.ptp_level: 
hw.vmm.amdvi.host_ptp: 
hw.vmm.amdvi.enable: 
hw.vmm.amdvi.count: 
hw.vmm.svm.num_asids: Number of ASIDs supported by this processor
hw.vmm.svm.disable_npf_assist: 
hw.vmm.svm.features: SVM features advertised by CPUID.8000000AH:EDX
hw.vmm.svm.vmcb_clean: 
hw.vmm.vrtc.flag_broken_time: Stop guest when invalid RTC time is detected
hw.vmm.iommu.enable: Enable use of I/O MMU (required for PCI passthrough).
hw.vmm.topology.cpuid_leaf_b: 
hw.vmm.trace_guest_exceptions: Trap into hypervisor on all guest exceptions and reflect them back
hw.vmm.halt_detection: Halt VM if all vcpus execute HLT with interrupts disabled
hw.mca.erratum383: Is the workaround for Erratum 383 on AMD Family 10h processors enabled?
hw.mca.intel6h_HSD131: Administrative toggle for logging of spurious corrected errors
hw.mca.amd10h_L1TP: Administrative toggle for logging of level one TLB parity (L1TP) errors
hw.mca.enabled: Administrative toggle for machine check support
hw.apic.enable_extint: Enable the ExtINT pin in the first I/O APIC
hw.spec_store_bypass_disable: Speculative Store Bypass Disable (0 - off, 1 - on, 2 - auto
hw.ibrs_disable: Disable Indirect Branch Restricted Speculation
hw.dmar.check_free: Check the GPA RBtree for free_down and free_after validity
hw.dmar.batch_coalesce: Number of qi batches between interrupt
hw.dmar.match_verbose: Verbose matching of the PCI devices to DMAR paths
hw.vmbus.pin_evttask: Pin event tasks to their respective CPU
hw.hvtimesync.sample_verbose: Increase sample request verbosity.
hw.hvtimesync.sample_thresh: Threshold that makes sample request trigger the sync (unit: ms).
hw.hvtimesync.ignore_sync: Ignore the sync request.
hw.storvsc.chan_cnt: # of channels to use
hw.storvsc.max_io: Hyper-V storage max io limit
hw.storvsc.ringbuffer_size: Hyper-V storage ringbuffer size
hw.storvsc.use_pim_unmapped: Optimize storvsc by using unmapped I/O
hw.hn.vf_xpnt_attwait: Extra wait for transparent VF attach routing; unit: seconds
hw.hn.vf_xpnt_accbpf: Accurate BPF for transparent VF
hw.hn.vf_transparent: Transparent VF mod
hw.hn.tx_agg_pkts: Packet transmission aggregation packet limit
hw.hn.tx_agg_size: Packet transmission aggregation size limit
hw.hn.lro_mbufq_depth: Depth of LRO mbuf queue
hw.hn.tx_swq_depth: Depth of IFQ or BUFRING
hw.hn.tx_ring_cnt: # of TX rings to use
hw.hn.chan_cnt: # of channels to use; each channel has one RX ring and one TX ring
hw.hn.use_if_start: Use if_start TX method
hw.hn.tx_taskq_mode: TX taskqueue modes: 0 - independent, 1 - share global tx taskqs, 2 - share event taskqs
hw.hn.tx_taskq_cnt: # of TX taskqueues
hw.hn.lro_entry_count: LRO entry count
hw.hn.direct_tx_size: Size of the packet for direct transmission
hw.hn.tx_chimney_size: Chimney send packet size limit
hw.hn.tso_maxlen: TSO burst limit
hw.hn.udpcs_fixup_mtu: UDP checksum fixup MTU threshold
hw.hn.enable_udp6cs: Offload UDP/IPv6 checksum
hw.hn.enable_udp4cs: Offload UDP/IPv4 checksum
hw.hn.trust_hostip: Trust ip packet verification on host side, when csum info is missing (global setting)
hw.hn.trust_hostudp: Trust udp datagram verification on host side, when csum info is missing (global setting)
hw.hn.trust_hosttcp: Trust tcp segement verification on host side, when csum info is missing (global setting)
hw.iavf.tx_itr: TX Interrupt Rate
hw.iavf.rx_itr: RX Interrupt Rate
hw.iavf.shared_debug_mask: Display debug statements that are printed in shared code
hw.iavf.core_debug_mask: Display debug statements that are printed in non-shared code
hw.iavf.enable_head_writeback: For detecting last completed TX descriptor by hardware, use value written by HW instead of checking descriptors
hw.ixl.tx_itr: TX Interrupt Rate
hw.ixl.rx_itr: RX Interrupt Rate
hw.ixl.shared_debug_mask: Display debug statements that are printed in shared code
hw.ixl.core_debug_mask: Display debug statements that are printed in non-shared code
hw.ixl.enable_head_writeback: For detecting last completed TX descriptor by hardware, use value written by HW instead of checking descriptors
hw.ixl.enable_vf_loopback: 
Determines mode that embedded device switch will use when SR-IOV is initialized:
	0 - Disable (VEPA)
	1 - Enable (VEB)
Enabling this will allow VFs in separate VMs to communicate over the hardware bridge.
hw.ixl.i2c_access_method: 
I2C access method that driver will use:
	0 - best available method
	1 - bit bang via I2CPARAMS register
	2 - register read/write via I2CCMD register
	3 - Use Admin Queue command (best)
Using the Admin Queue is only supported on 710 devices with FW version 1.7 or higher
hw.ixl.enable_tx_fc_filter: Filter out packets with Ethertype 0x8808 from being sent out by non-HW sources
hw.bxe.udp_rss: UDP RSS support
hw.bxe.autogreeen: AutoGrEEEn support
hw.bxe.mrrs: PCIe maximum read request size
hw.bxe.max_aggregation_size: max aggregation size
hw.bxe.rx_budget: Rx processing budget
hw.bxe.hc_tx_ticks: Host Coalescing Tx ticks
hw.bxe.hc_rx_ticks: Host Coalescing Rx ticks
hw.bxe.max_rx_bufs: Maximum Number of Rx Buffers Per Queue
hw.bxe.queue_count: Multi-Queue queue count
hw.bxe.interrupt_mode: Interrupt (MSI-X/MSI/INTx) mode
hw.bxe.debug: Debug logging mode
hw.psm.elantech_support: Enable support for Elantech touchpads
hw.psm.trackpoint_support: Enable support for IBM/Lenovo TrackPoint
hw.psm.synaptics_support: Enable support for Synaptics touchpads
hw.psm.tap_enabled: Enable tap and drag gestures
hw.lower_amd64_sharedpage: Lower sharedpage to work around Ryzen issue with executing code near the top of user memory
hw.lazy_fpu_switch: Lazily load FPU context after context switch
hw.bus.devctl_queue: devctl queue length
hw.bus.devctl_disable: devctl disable -- deprecated
hw.intr_storm_threshold: Number of consecutive interrupts before storm protection is enabled
hw.xbd.xbd_enable_indirect: Enable xbd indirect segments
hw.vtnet.rx_process_limit: Limits the number RX segments processed in a single pass
hw.vtnet.mq_max_pairs: Sets the maximum number of Multi Queue pairs
hw.vtnet.mq_disable: Disables Multi Queue support
hw.vtnet.lro_disable: Disables TCP Large Receive Offload
hw.vtnet.tso_disable: Disables TCP Segmentation Offload
hw.vtnet.csum_disable: Disables receive and send checksum offload
hw.usb.ums.debug: Debug level
hw.usb.uhid.debug: Debug level
hw.usb.rsu.debug: Debug level
hw.usb.ukbd.pollrate: Force this polling rate, 1-1000Hz
hw.usb.ukbd.no_leds: Disables setting of keyboard leds
hw.usb.ukbd.debug: Debug level
hw.usb.full_ddesc: USB always read complete device descriptor, if set
hw.usb.no_cs_fail: USB clear stall failures are ignored, if set
hw.usb.proc.debug: Debug level
hw.usb.disable_port_power: Set to disable all USB port power.
hw.usb.disable_enumeration: Set to disable all USB device enumeration. This can secure against USB devices turning evil, for example a USB memory stick becoming a USB keyboard.
hw.usb.power_timeout: USB power timeout
hw.usb.uhub.debug: Debug level
hw.usb.ugen.debug: Debug level
hw.usb.usb_lang_mask: Preferred USB language mask
hw.usb.usb_lang_id: Preferred USB language ID
hw.usb.template: Selected USB device side template
hw.usb.dev.debug: Debug Level
hw.usb.timings.extra_power_up_time: Extra PowerUp Time
hw.usb.timings.resume_recovery: Resume Recovery
hw.usb.timings.resume_wait: Resume Wait
hw.usb.timings.resume_delay: Resume Delay
hw.usb.timings.set_address_settle: Set Address Settle
hw.usb.timings.port_resume_delay: Port Resume Delay
hw.usb.timings.port_powerup_delay: Port PowerUp Delay
hw.usb.timings.port_reset_recovery: Port Reset Recovery
hw.usb.timings.port_root_reset_delay: Root Port Reset Delay
hw.usb.timings.port_reset_delay: Port Reset Delay
hw.usb.debug: Debug level
hw.usb.umass.throttle: Forced delay between commands in milliseconds
hw.usb.umass.debug: umass debug level
hw.usb.no_shutdown_wait: No USB device waiting at system shutdown.
hw.usb.no_suspend_wait: No USB device waiting at system suspend.
hw.usb.no_boot_wait: No USB device enumerate waiting at boot.
hw.usb.ctrl.debug: Debug level
hw.usb.xhci.ctlstep: Set to enable control endpoint status stage stepping
hw.usb.xhci.dma32: Set to only use 32-bit DMA for the XHCI controller
hw.usb.xhci.use_polling: Set to enable software interrupt polling for the XHCI controller
hw.usb.xhci.xhci_port_route: Routing bitmap for switching EHCI ports to the XHCI controller
hw.usb.xhci.debug: Debug level
hw.usb.xhci.streams: Set to enable streams mode support
hw.usb.uhci.loop: uhci noloop
hw.usb.uhci.debug: uhci debug level
hw.usb.ohci.debug: ohci debug level
hw.usb.ehci.lostintrbug: Enable lost interrupt bug workaround
hw.usb.ehci.iaadbug: Enable doorbell bug workaround
hw.usb.ehci.no_hs: Disable High Speed USB
hw.usb.ehci.debug: Debug level
hw.broken_txfifo: UART FIFO has QEMU emulation bug
hw.syscons.sc_no_suspend_vtswitch: Disable VT switch before suspend.
hw.snd.maxautovchans: maximum virtual channel
hw.snd.default_unit: default sound device
hw.snd.default_auto: assign default unit to a newly attached device
hw.snd.verbose: verbosity level
hw.snd.vpc_mixer_bypass: control channel pcm/rec volume, bypassing real mixer device
hw.snd.feeder_rate_quality: sample rate converter quality (0=low .. 4=high)
hw.snd.feeder_rate_round: sample rate converter rounding threshold
hw.snd.feeder_rate_max: maximum allowable rate
hw.snd.feeder_rate_min: minimum allowable rate
hw.snd.feeder_rate_polyphase_max: maximum allowable polyphase entries
hw.snd.feeder_eq_exact_rate: force exact rate validation
hw.snd.basename_clone: DSP basename cloning (0: Disable; 1: Enabled)
hw.snd.compat_linux_mmap: linux mmap compatibility (-1=force disable 0=auto 1=force enable)
hw.snd.syncdelay: append (0-1000) millisecond trailing buffer delay on each sync
hw.snd.usefrags: prefer setfragments() over setblocksize()
hw.snd.vpc_0db: 0db relative level
hw.snd.vpc_autoreset: automatically reset channels volume to 0db
hw.snd.timeout: interrupt timeout (1 - 10) seconds
hw.snd.latency_profile: buffering latency profile (0=aggressive 1=safe)
hw.snd.latency: buffering latency (0=low ... 10=high)
hw.sdhci.enable_msi: Enable MSI interrupts
hw.sdhci.quirk_set: Mask of quirks to set
hw.sdhci.quirk_clear: Mask of quirks to clear
hw.sdhci.debug: Debug level
hw.puc.msi_disable: Disable use of MSI interrupts by puc(9)
hw.pci.host_mem_start: Limit the host bridge memory to being above this address.
hw.pci.mcfg: Enable support for PCI-e memory mapped config access
hw.pci.default_vgapci_unit: Default VGA-compatible display
hw.pci.enable_pcie_hp: Enable support for native PCI-express HotPlug.
hw.pci.clear_pcib: Clear firmware-assigned resources for PCI-PCI bridge I/O windows.
hw.pci.iov_max_config: Maximum allowed size of SR-IOV configuration.
hw.pci.clear_aer_on_attach: Clear port and device AER state on driver attach
hw.pci.enable_ari: Enable support for PCIe Alternative RID Interpretation
hw.pci.clear_buses: Ignore firmware-assigned bus numbers.
hw.pci.clear_bars: Ignore firmware-assigned resources for BARs.
hw.pci.usb_early_takeover: Enable early takeover of USB controllers. Disable this if you depend on BIOS emulation of USB devices, that is you use USB devices (like keyboard or mouse) but do not load USB drivers
hw.pci.honor_msi_blacklist: Honor chipset blacklist for MSI/MSI-X
hw.pci.msix_rewrite_table: Rewrite entire MSI-X table when updating MSI-X entries
hw.pci.enable_msix: Enable support for MSI-X interrupts
hw.pci.enable_msi: Enable support for MSI interrupts
hw.pci.do_power_suspend: Transition from D0 -> D3 on suspend.
hw.pci.do_power_resume: Transition from D3 -> D0 on resume.
hw.pci.do_power_nodriver: Place a function into D3 state when no driver attaches to it.  0 means disable.  1 means conservatively place devices into D3 state.  2 means aggressively place devices into D3 state.  3 means put absolutely everything in D3 state.
hw.pci.realloc_bars: Attempt to allocate a new range for any BARs whose original firmware-assigned ranges fail to allocate during the initial device scan.
hw.pci.enable_io_modes: Enable I/O and memory bits in the config register.  Some BIOSes do not enable these bits correctly.  We'd like to do this all the time, but there are some peripherals that this causes problems with.
hw.pcic.pd6722_vsense: Select CL-PD6722's VSENSE method.  VSENSE is used to determine the voltage of inserted cards.  The CL-PD6722 has two methods to determine the voltage of the card.  0 means assume a 5.0V card and do not check.  1 means use the same method that the CL-PD6710 uses (default).  2 means use the same method as the CL-PD6729.  2 is documented in the datasheet as being the correct way, but 1 seems to give better results on more laptops.
hw.pcic.intr_mask: Mask of allowable interrupts for this laptop.  The default is generally correct, but some laptops do not route all the IRQ pins to the bridge to save wires.  Sometimes you need a more restrictive mask because some of the hardware in your laptop may not have a driver so its IRQ might not be allocated.
hw.cbb.debug: Verbose cardbus bridge debugging
hw.cbb.start_32_io: Starting ioport for 32-bit cards
hw.cbb.start_16_io: Starting ioport for 16-bit cards
hw.cbb.start_memory: Starting address for memory allocations
hw.pccard.cis_debug: pccard CIS debug
hw.pccard.debug: pccard debug
hw.nvme.use_nvd: 1 = Create NVD devices, 0 = Create NDA devices
hw.nvd.delete_max: nvd maximum BIO_DELETE size in bytes
hw.mwl.rxdmalow: min free rx buffers before restarting traffic
hw.mwl.rxquota: max rx buffers to process per interrupt
hw.mwl.txcoalesce: tx buffers to send at once
hw.mwl.txbuf: tx buffers allocated
hw.mwl.rxbuf: rx buffers allocated
hw.mmcsd.cache: Device R/W cache enabled if present
hw.mmc.debug: Debug level
hw.mfi.mrsas_enable: Allow mrasas to take newer cards
hw.mfi.msi: Enable use of MSI interrupts
hw.mfi.cmd_timeout: Command timeout (in seconds)
hw.mfi.polled_cmd_timeout: Polled command timeout - used for firmware flash etc (in seconds)
hw.mfi.detect_jbod_change: Detect a change to a JBOD
hw.mfi.max_cmds: Max commands limit (-1 = controller limit)
hw.mfi.event_class: event message class
hw.mfi.event_locale: event message locale
hw.malo.pci.msi_disable: MSI disabled
hw.malo.txbuf: tx buffers allocated
hw.malo.rxquota: max rx buffers to process per interrupt
hw.malo.rxbuf: rx buffers allocated
hw.malo.txcoalesce: tx buffers to send at once
hw.ix.enable_rss: Enable Receive-Side Scaling (RSS)
hw.ix.enable_fdir: Enable Flow Director
hw.ix.unsupported_sfp: Allow unsupported SFP modules...use at your own risk
hw.ix.enable_msix: Enable MSI-X interrupts
hw.ix.advertise_speed: Default advertised speed for all adapters
hw.ix.flow_control: Default flow control used for all adapters
hw.ix.max_interrupt_rate: Maximum interrupts per second
hw.em.max_interrupt_rate: Maximum interrupts per second
hw.em.eee_setting: Enable Energy Efficient Ethernet
hw.em.rx_process_limit: Maximum number of received packets to process at a time, -1 means unlimited
hw.em.sbp: Show bad packets in promiscuous mode
hw.em.smart_pwr_down: Set to true to leave smart power down enabled on newer adapters
hw.em.rx_abs_int_delay: Default receive interrupt delay limit in usecs
hw.em.tx_abs_int_delay: Default transmit interrupt delay limit in usecs
hw.em.rx_int_delay: Default receive interrupt delay in usecs
hw.em.tx_int_delay: Default transmit interrupt delay in usecs
hw.em.disable_crc_stripping: Disable CRC Stripping
hw.efi.poweroff: If true, use EFI runtime services to power off in preference to ACPI
hw.cardbus.cis_debug: CardBus CIS debug
hw.cardbus.debug: CardBus debug
hw.bge.allow_asf: Allow ASF mode if available
hw.bce.rx_ticks: Receive ticks count
hw.bce.rx_ticks_int: Receive ticks count during interrupt
hw.bce.rx_quick_cons_trip: Receive BD trip point
hw.bce.rx_quick_cons_trip_int: Receive BD trip point duirng interrupts
hw.bce.tx_ticks: Transmit ticks count
hw.bce.tx_ticks_int: Transmit ticks count during interrupt
hw.bce.tx_quick_cons_trip: Transmit BD trip point
hw.bce.tx_quick_cons_trip_int: Transmit BD trip point during interrupts
hw.bce.strict_rx_mtu: Enable/Disable strict RX frame size checking
hw.bce.hdr_split: Frame header/payload splitting Enable/Disable
hw.bce.tx_pages: Transmit buffer descriptor pages (1 page = 255 buffer descriptors)
hw.bce.rx_pages: Receive buffer descriptor pages (1 page = 255 buffer descriptors)
hw.bce.msi_enable: MSI-X|MSI|INTx selector
hw.bce.tso_enable: TSO Enable/Disable
hw.bce.verbose: Verbose output enable/disable
hw.ath.txbuf_mgmt: tx (mgmt) buffers allocated
hw.ath.txbuf: tx buffers allocated
hw.ath.rxbuf: rx buffers allocated
hw.ata.ata_dma_check_80pin: Check for 80pin cable before setting ATA DMA mode
hw.amr.force_sg32: Force the AMR driver to use 32bit scatter gather
hw.aac.enable_msi: Enable MSI interrupts
machdep.disable_tsc_calibration: Disable TSC frequency calibration
machdep.disable_tsc: Disable x86 Time Stamp Counter
machdep.disable_msix_migration: Disable migration of MSI-X interrupts between CPUs
machdep.num_msi_irqs: Number of IRQs reserved for MSI and MSI-X interrupts
machdep.hyperthreading_allowed: Use Intel HTT logical CPUs
machdep.disable_mtrrs: Disable MTRRs.
machdep.kdb_on_nmi: Go to KDB on NMI with unknown source
machdep.nmi_is_broadcast: Chipset NMI is broadcast
machdep.panic_on_nmi: Panic on NMI raised by hardware failure
machdep.idle_mwait: Use MONITOR/MWAIT for short idle
machdep.syscall_ret_flush_l1d: Flush L1D on syscall return with error (0 - off, 1 - on, 2 - use hw only, 3 - use sw only
machdep.nmi_flush_l1d_sw: Flush L1 Data Cache on NMI exit, software bhyve L1TF mitigation assist
machdep.uprintf_signal: Print debugging information on trap signal to ctty
machdep.prot_fault_translation: Select signal to deliver on protection fault
machdep.max_ldt_segment: Maximum number of allowed LDT segments in the single address space
machdep.dump_retry_count: Number of times dump has to retry before bailing out
machdep.rtc_save_period: Save system time to RTC with this period (in seconds)
machdep.efi_rt_handle_faults: Call EFI RT methods with fault handler wrapper around
dev.drm.always_interruptible: always allow a thread to be interrupted in driver wait
dev.drm.error_panic: panic if an ERROR is hit
dev.drm.drm_debug_persist: keep drm debug flags post-load
dev.drm.skip_ddb: go straight to dumping core
dev.drm.drm_debug: drm debug flags
dev.uhub.4.disable_port_power: Set to disable USB port power on this USB HUB.
dev.uhub.4.disable_enumeration: Set to disable enumeration on this USB HUB.
dev.uhub.3.disable_port_power: Set to disable USB port power on this USB HUB.
dev.uhub.3.disable_enumeration: Set to disable enumeration on this USB HUB.
dev.uhub.2.disable_port_power: Set to disable USB port power on this USB HUB.
dev.uhub.2.disable_enumeration: Set to disable enumeration on this USB HUB.
dev.uhub.1.disable_port_power: Set to disable USB port power on this USB HUB.
dev.uhub.1.disable_enumeration: Set to disable enumeration on this USB HUB.
dev.uhub.0.disable_port_power: Set to disable USB port power on this USB HUB.
dev.uhub.0.disable_enumeration: Set to disable enumeration on this USB HUB.
dev.pcm.1.bitperfect: bit-perfect playback/recording (0=disable, 1=enable)
dev.pcm.1.rec.vchanformat: virtual channel mixing format
dev.pcm.1.rec.vchanrate: virtual channel mixing speed/rate
dev.pcm.1.rec.vchanmode: vchan format/rate selection: 0=fixed, 1=passthrough, 2=adaptive
dev.pcm.1.rec.vchans: total allocated virtual channel
dev.pcm.1.play.vchanformat: virtual channel mixing format
dev.pcm.1.play.vchanrate: virtual channel mixing speed/rate
dev.pcm.1.play.vchanmode: vchan format/rate selection: 0=fixed, 1=passthrough, 2=adaptive
dev.pcm.1.play.vchans: total allocated virtual channel
dev.pcm.0.bitperfect: bit-perfect playback/recording (0=disable, 1=enable)
dev.pcm.0.rec.vchanformat: virtual channel mixing format
dev.pcm.0.rec.vchanrate: virtual channel mixing speed/rate
dev.pcm.0.rec.vchanmode: vchan format/rate selection: 0=fixed, 1=passthrough, 2=adaptive
dev.pcm.0.rec.vchans: total allocated virtual channel
dev.pcm.0.play.vchanformat: virtual channel mixing format
dev.pcm.0.play.vchanrate: virtual channel mixing speed/rate
dev.pcm.0.play.vchanmode: vchan format/rate selection: 0=fixed, 1=passthrough, 2=adaptive
dev.pcm.0.play.vchans: total allocated virtual channel
dev.em.0.iflib.override_nrxds: list of # of rx descriptors to use, 0 = use default #
dev.em.0.iflib.override_ntxds: list of # of tx descriptors to use, 0 = use default #
dev.em.0.iflib.tx_abdicate: cause tx to abdicate instead of running to completion
dev.em.0.iflib.rx_budget: set the rx budget
dev.em.0.iflib.disable_msix: disable MSI-X (default 0)
dev.em.0.iflib.override_qs_enable: permit #txq != #rxq
dev.em.0.iflib.override_nrxqs: # of rxqs to use, 0 => use default #
dev.em.0.iflib.override_ntxqs: # of txqs to use, 0 => use default #
security.mac.ntpd.uid: User id for ntpd user
security.mac.ntpd.enabled: Enable mac_ntpd policy
security.bsd.stack_guard_page: Specifies the number of guard pages for a stack that grows
security.bsd.unprivileged_mlock: Allow non-root users to call mlock(2)
security.bsd.suser_enabled: processes with uid 0 have privilege
security.bsd.map_at_zero: Permit processes to map an object at virtual address 0.
security.jail.param.ip6.: Jail IPv6 address virtualization
security.jail.param.ip4.: Jail IPv4 address virtualization
security.jail.param.vnet: Virtual network stack
security.jail.param.osrelease: Jail value for kern.osrelease and uname -r
security.jail.param.osreldate: Jail value for kern.osreldate and uname -K
security.jail.param.path: Jail root path
security.jail.param.jid: Jail ID
compat.linuxkpi.enable_gvt: Enable support for Intel GVT-g graphics virtualization host support(default:false)
compat.linuxkpi.enable_dpcd_backlight: Enable support for DPCD backlight control (default:false)
compat.linuxkpi.inject_load_failure: Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)
compat.linuxkpi.enable_dp_mst: Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)
compat.linuxkpi.guc_log_level: GuC firmware logging level (-1:disabled (default), 0-3:enabled)
compat.linuxkpi.enable_guc: Enable GuC load for GuC submission and/or HuC load. Required functionality can be selected using bitmask values. (-1=auto, 0=disable [default], 1=GuC submission, 2=HuC load)
compat.linuxkpi.edp_vswing: Ignore/Override vswing pre-emph table selection from VBT (0=use value from vbt [default], 1=low power swing(200mV),2=default swing(400mV))
compat.linuxkpi.nuclear_pageflip: Force enable atomic functionality on platforms that don't have full support yet.
compat.linuxkpi.verbose_state_checks: Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.
compat.linuxkpi.mmio_debug: Enable the MMIO debug code for the first N failures (default: off). This may negatively affect performance.
compat.linuxkpi.enable_cmd_parser: Enable command parsing (true=enabled [default], false=disabled)
compat.linuxkpi.disable_display: Disable display (default: false)
compat.linuxkpi.invert_brightness: Invert backlight brightness (-1 force normal, 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem vendor and subsystem device ID to dri-devel@lists.freedesktop.org, if your machine needs it. It will then be included in an upcoming module version.
compat.linuxkpi.force_reset_modeset_test: Force a modeset during gpu reset for testing (default:false). For developers only.
compat.linuxkpi.load_detect_test: Force-enable the VGA load detect code for testing (default:false). For developers only.
compat.linuxkpi.prefault_disable: Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only.
compat.linuxkpi.fastboot: Try to skip unnecessary mode sets at boot time (default: false)
compat.linuxkpi.enable_ips: Enable IPS (default: true)
compat.linuxkpi.disable_power_well: Disable display power wells when possible (-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)
compat.linuxkpi.alpha_support: Enable alpha quality driver support for latest hardware. See also CONFIG_DRM_I915_ALPHA_SUPPORT.
compat.linuxkpi.enable_psr: Enable PSR (0=disabled, 1=enabled - link mode chosen per-platform, 2=force link-standby mode, 3=force link-off mode) Default: -1 (use per-chip default)
compat.linuxkpi.enable_ppgtt: Override PPGTT usage. (-1=auto [default], 0=disabled, 1=aliasing, 2=full, 3=full with extended address space)
compat.linuxkpi.enable_hangcheck: Periodically check GPU activity for detecting hangs. WARNING: Disabling this can cause system wide hangs. (default: true)
compat.linuxkpi.error_capture: Record the GPU state following a hang. This information in /sys/class/drm/card<N>/error is vital for triaging and debugging hangs.
compat.linuxkpi.reset: Attempt GPU resets (0=disabled, 1=full gpu reset, 2=engine reset [default])
compat.linuxkpi.vbt_sdvo_panel_type: Override/Ignore selection of SDVO panel mode in the VBT (-2=ignore, -1=auto [default], index in VBT BIOS table)
compat.linuxkpi.panel_use_ssc: Use Spread Spectrum Clock with panels [LVDS/eDP] (default: auto from VBT)
compat.linuxkpi.lvds_channel_mode: Specify LVDS channel mode (0=probe BIOS [default], 1=single-channel, 2=dual-channel)
compat.linuxkpi.enable_fbc: Enable frame buffer compression for power savings (default: -1 (use per-chip default))
compat.linuxkpi.enable_dc: Enable power-saving display C-states. (-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6)
compat.linuxkpi.panel_ignore_lid: Override lid status (0=autodetect, 1=autodetect disabled [default], -1=force lid closed, -2=force lid open)
compat.linuxkpi.modeset: Use kernel modesetting [KMS] (0=disable, 1=on, -1=force vga console preference [default])
compat.linuxkpi.timestamp_precision_usec: Max. error on timestamps [usecs]
compat.linuxkpi.vblankoffdelay: Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)
compat.linuxkpi.poll: help drm kms poll
compat.linuxkpi.drm_fbdev_overalloc: Overallocation of the fbdev buffer (%) [default=100]
compat.linuxkpi.fbdev_emulation: Enable legacy fbdev emulation [default=true]
compat.linuxkpi.edid_firmware: Do not probe monitor, use specified EDID blob from built-in data or /lib/firmware instead. 
compat.linuxkpi.edid_fixup: Minimum number of valid EDID header bytes (0-8, default 6)
compat.linuxkpi.debug: Enable debug output, where each bit enables a debug category.
		Bit 0 (0x01) will enable CORE messages (drm core code)
		Bit 1 (0x02) will enable DRIVER messages (drm controller code)
		Bit 2 (0x04) will enable KMS messages (modesetting code)
		Bit 3 (0x08) will enable PRIME messages (prime code)
		Bit 4 (0x10) will enable ATOMIC messages (atomic code)
		Bit 5 (0x20) will enable VBL messages (vblank code)
		Bit 7 (0x80) will enable LEASE messages (leasing code)
compat.linuxkpi.dp_aux_i2c_transfer_size: Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)
compat.linuxkpi.dp_aux_i2c_speed_khz: Assumed speed of the i2c bus in kHz, (1-400, default 10)
compat.ia32.maxvmem: 
compat.ia32.maxssiz: 
compat.ia32.maxdsiz: