Linux RAID0

linux-raid0.txt

root@trusty01:~# fdisk -l /dev/sdb

Disk /dev/sdb: 256.1 GB, 256060514304 bytes
234 heads, 63 sectors/track, 33924 cylinders, total 500118192 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xba903263

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048   500118191   250058072   fd  Linux raid autodetect
root@trusty01:~# fdisk -l /dev/sdc

Disk /dev/sdc: 256.1 GB, 256060514304 bytes
168 heads, 63 sectors/track, 47252 cylinders, total 500118192 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x6f331eaa

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1            2048   500118191   250058072   fd  Linux raid autodetect
root@trusty01:~# mdadm --create --verbose /dev/md0 --level=stripe --raid-devices=2 /dev/sdb1 /dev/sdc1 
mdadm: chunk size defaults to 512K
mdadm: /dev/sdb1 appears to contain an ext2fs file system
    size=245366784K  mtime=Mon Nov 30 21:28:24 2015
mdadm: /dev/sdc1 appears to contain an ext2fs file system
    size=250058072K  mtime=Mon Nov 30 21:27:04 2015
Continue creating array? y          
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
root@trusty01:~# mkfs -t ext4 /dev/md0
mke2fs 1.42.9 (4-Feb-2014)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=128 blocks, Stripe width=256 blocks
31260672 inodes, 125028864 blocks
6251443 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
3816 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 
	102400000

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done     
root@trusty01:~# tune2fs -l /dev/md0
tune2fs 1.42.9 (4-Feb-2014)
Filesystem volume name:   <none>
Last mounted on:          <not available>
Filesystem UUID:          58768622-3399-4da0-a79c-e9742096453e
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash 
Default mount options:    user_xattr acl
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              31260672
Block count:              125028864
Reserved block count:     6251443
Free blocks:              123016216
Free inodes:              31260661
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      994
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
RAID stride:              128
RAID stripe width:        256
Flex block group size:    16
Filesystem created:       Mon Nov 30 21:44:38 2015
Last mount time:          Mon Nov 30 21:45:03 2015
Last write time:          Mon Nov 30 21:45:03 2015
Mount count:              1
Maximum mount count:      -1
Last checked:             Mon Nov 30 21:44:38 2015
Check interval:           0 (<none>)
Lifetime writes:          133 MB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:	          256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      08de8825-c550-463e-a206-42ecf45b0fd7
Journal backup:           inode blocks
root@trusty01:/scratch/ricardo# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sdc1 during installation
UUID=2cf4b98a-66e5-47dd-a6ed-5745a2e9fe12 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sdc2 during installation
UUID=9e3f7a98-59d5-4036-8151-88c4d7b34f75 none            swap    sw              0       0
# md0
UUID=58768622-3399-4da0-a79c-e9742096453e /scratch ext4 defaults,errors=remount-ro,nobootwait,noatime 0 0
# save the array setup to /etc/mdadm/mdadm.conf
root@trusty01:~# /usr/share/mdadm/mkconf > /etc/mdadm/mdadm.conf