[olug] IO Performance

[jay swackhamer]

It appears that a code-level on the IBM XIV disk array that relates to
replication has more to do with IO performance than Linux Tuning.

Now we are running batch schedules through Oracle faster than previously, so
there was some benefit, and now I can tweak/tune these some more,
to get to the best numbers for the workload.

On the road to this discovery, I found these parameters related to IO
performance.

Does anyone else have any IO related tuning tips?

echo 10 > /proc/sys/vm/swappiness
echo 1024 > /proc/sys/vm/min_free_kbytes
sysctl -w vm.pagecache="1 10 30"
echo 192 > /sys/module/qla2xxx/parameters/ql2xmaxqdepth
multipath -ll > /tmp/multipath.txt
for i in `grep sd /tmp/multipath.txt | awk ' { print $3 } '`
do
    echo 192 > /sys/block/$i/device/queue_depth
    echo 384 > /sys/block/$i/queue/nr_requests
    echo 512 > /sys/block/$i/queue/read_ahead_kb
    echo deadline > /sys/block/$i/queue/scheduler
done

for i in `mount | grep vg | awk ' { print $1 } '`
do
    mount -o remount,noatime,async $i
done