SSD optimizations

See http://tombuntu.com/index.php/2008/09/04/four-tweaks-for-using-linux-with-solid-state-drives/

/boot, /home, /swap on raptor /dev/sda / on RevoDrive /dev/md0 (/dev/sdc, /dev/sdd)

1 put noatime option in /etc/fstab

2 disable the elevator scheduler, put these in /etc/rc.local

echo noop > /sys/block/sdc/queue/scheduler
echo noop > /sys/block/sdd/queue/scheduler

3 manage write caching via /etc/hdparm.conf

# Raptor drive
/dev/sda {
	write_cache = on
}

# Caviar drive
/dev/sdb {
	write_cache = on
}

# SSD RevoDrive
/dev/sdc {
	write_cache = off
}

/dev/sdd {
	write_cache = off
}

Test results

the new Black drive is faster than the Velociraptor. The SSD is FAST and the Green is slow. No surprises there. Tested with hdparm -t command.

# RevoDrive
Timing buffered disk reads:  1028 MB in  3.01 seconds = 341.87 MB/sec

bonnie++
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
raven           16G  1958  99 498533  42 193488  24  4443  98 501475  27  6290 125
Latency              6425us     378ms   52859us    2402us    9032us    4884us
Version  1.96       ------Sequential Create------ --------Random Create--------
raven               -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16  7355  95 +++++ +++ +++++ +++  7916  94 +++++ +++ 24012  89
Latency               490us     113us      74us     265us      32us     763us

1.96,1.96,raven,1,1289707876,16G,,1958,99,498533,42,193488,24,4443,98,501475,27,6290,125,16,,,,,7355,95,+++++,+++,+++++,+++,7916,94,+++++,+++,24012,89,6425us,378ms,52859us,2402us,9032us,4884us,490us,113us,74us,265us,32us,763us

# Velociraptor
Timing buffered disk reads:  358 MB in  3.01 seconds = 118.84 MB/sec
bonnie++ -d /home/bwilson/foo

# Caviar Green
Timing buffered disk reads:  198 MB in  3.00 seconds =  65.97 MB/sec

# Caviar Black
Timing buffered disk reads:  442 MB in  3.01 seconds = 146.99 MB/sec