On 9-4-2009 16:09 Kevin Grittner wrote:
I haven't benchmarked it, but when one of our new machines seemed a little sluggish, I found this hadn't been set. Setting this and rebooting Linux got us back to our normal level of performance.
Why would you reboot after changing the elevator? For 2.6-kernels, it can be adjusted on-the-fly for each device separately (echo 'deadline' > /sys/block/sda/queue/scheduler).
I saw a nice reduction in load and slowness too after adjusting the cfq to deadline for a machine that was at its maximum I/O-capacity on a raid-array. Apart from deadline, 'noop' should also be interesting for RAID and SSD-owners, as it basically just forwards the I/O-request to the device and doesn't do much (if any?) scheduling.
Best regards, Arjen -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
