Some VMware related I/O speed optimizations
While studying the documentation to Lustre (a distributed Linux filesystem) I found this:
Choosing an alternate scheduler is an absolutely necessary step
to optimally configure Lustre for the best performance. The “cfq” and “as” schedulers should never be used
for server platform.
So I revised my VMware installation and found out that all my guest are configured to use the deadline scheduler. But as it seemed my host did use the cfq. In the user guide there was described how to change the used scheduler while running the system (where hda is the disk):
[root@cfs2]# cat /sys/block/hda/queue/scheduler noop [anticipatory] deadline cfq [root@cfs2 ~]# echo deadline > /sys/block/hda/queue/scheduler [root@cfs2 ~]# cat /sys/block/hda/queue/scheduler noop anticipatory [deadline] cfq
So I changed the scheduler and it seems the overall performance is dramatically increased.