Geoff Swan wrote:
On 2015-04-23 4:07 PM, Ulrich Windl wrote:
Geoff Swan <[email protected]> schrieb am 22.04.2015 um 23:18 in Nachricht
<[email protected]>:
[...]
Free stats look fine to me. No swap is being used, or has been used yet
on this system.
total used free shared buffers cached
Mem: 132005400 21928192 110077208 10612 363064 19230072
-/+ buffers/cache: 2335056 129670344
Swap: 8388604 0 8388604
The effect I am seeing is that despite a reasonably fast disc system,
the kernel writing of dirty pages is painfully slow.
So disk I/O stats is also available via sar. May we see them? Finally there's
blktrace where you can follow the timing and positions of each individual block
being written, but that's not quite easy to run and analyze (unless I missed
the easy way).
I suspect scattered writes that bring your I/O rate down.
Regards,
Ulrich
sysstat (and sar) is not installed on this system, so I can't give you
that output.
As I said in my previous email - use iostat and/or vmstat to monitor
paging activity and system wait time. You can also install atop and get
all of the relevant stats on one screen.
http://www.atoptool.nl/
I find it indispensible these days.
--
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/
