BrianRossmajer

http://pl.atyp.us/wordpress/index.php/2009/09/file-transfer-fun/

File Transfer Fun
17 September, 2009 8:32 am
I’ve written before about the extreme usefulness of sshfs for accessing files remotely without having to install server software. It continues to be an important part of my toolbox, as does its cousin CurlFtpFS which – unlike sshfs – I can even use to mount a directory here on my web host. Of course, either becomes even more useful when combined with some easy method of synchronization. You probably have rsync already. You can also use Unison if you need bidirectional synchronization – which you generally will if you’re trying to use a single directory somewhere as a “drop box” to share between multiple machines.

I just found another sshfs trick today. If the connection between your two machines is already secure – e.g. on the same private network or connected via a secure VPN/tunnel – you might want to avoid an extra round of encryption and decryption by using the “-o directport” option to sshfs. T

voluntas

### KERNEL TUNING ###

# Increase size of file handles and inode cache
fs.file-max = 2097152

# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2

vongosling

LInux

Three system configuration parameters must be set to support a large number of open files and TCP connections with large bursts of messages. Changes can be made using the /etc/rc.d/rc.local or /etc/sysctl.conf script to preserve changes after reboot.

1. /proc/sys/fs/file-max: The maximum number of concurrently open files.

fs.file-max = 1000000

2. /proc/sys/net/ipv4/tcp_max_syn_backlog: Maximum number of remembered connection requests, which are still did not receive an acknowledgment from connecting client. The default value is 1024 for systems with more than 128Mb of memory, and 128 for low memory machines.

net.ipv4.tcp_max_syn_backlog = 3240000

3. /proc/sys/net/core/somaxconn: Limit of socket listen() backlog, known in userspace as SOMAXCONN. Defaults to 128.

net.core.somaxconn = 3240000