AdminSysGNULinux

Voir :

• https://linuxfr.org/users/xunfr/journaux/how-to-bench-this-ssd
• https://blog.hbis.fr/
• http://strugglers.net/~andy/blog/2015/08/09/ssds-and-linux-native-command-queuing/
• https://www.thomas-krenn.com/en/wiki/Linux_I/O_Performance_Tests_using_dd
• https://medium.com/@kenichishibata/test-i-o-performance-of-linux-using-dd-a5074f1de9ce
• https://linuxfr.org/users/xunfr/journaux/how-to-bench-this-ssd
• http://drup.org/benchmarking-linux
• https://wiki.mikejung.biz/Benchmarking

Voir :

• atop
• stress-ng
• iozone3

stress-ng --all 0 --maximize --aggressive

iostat -hx 5
iostat -xmt 1

Linux : tester les performances I/O

hdparm -t -T /dev/sda
dd bs=8192 count=$((4096 * 128)) if=/dev/zero of=test conv=fdatasync
bonnie++ -d /mnt -r 8000 -u toto

#time -p dd if=/dev/zero of=/tmp/test1.img bs=1M count=500 oflag=dsync
#time -p dd if=/dev/zero of=/tmp/test1.img bs=500M count=1 oflag=dsync
time -p dd if=/dev/zero of=/tmp/test1.img bs=8192 count=$((8192 * 64)) oflag=dsync

sudo apt-get install sysbench
# --file-test-mode=STRING       test mode {seqwr, seqrewr, seqrd, rndrd, rndwr, rndrw}
sysbench --test=fileio --file-test-mode=seqwr run
 
sysbench --test=fileio --file-total-size=4G prepare
sysbench --test=fileio --file-total-size=4G --file-test-mode=rndrd --max-time=5 run
sysbench --test=fileio --file-total-size=4G --file-test-mode=rndwr --max-time=5 run
sysbench --test=fileio --file-total-size=4G cleanup

blockdev --report
blockdev --getra /dev/sda
blockdev --setra 256 /dev/sdc
cat /sys/block/sda/queue/read_ahead_kb

Source https://www.geekarea.fr/wordpress/?p=769

apt-get install fio

cat > plop.fio << EOF
[global]
bs=64k
direct=1
rw=randrw
ioengine=libaio
iodepth=2
zonesize=256m
zoneskip=2g
write_bw_log=str
 
[/dev/vdb]
EOF
 
fio plop.fio

# cat /sys/block/sda/queue/scheduler
noop deadline [cfq]

/etc/default/grub

# GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash elevator=noop"

Voir :

• https://access.redhat.com/solutions/56117