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Re: Antw: Re: Slapd running very slow

Geoff Swan wrote:



On 2015-04-23 4:07 PM, Ulrich Windl wrote:

Geoff Swan <gswan3@bigpond.net.au> schrieb am 22.04.2015 um 23:18 in Nachricht

<5538100A.3060301@bigpond.net.au>:

[...]

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.

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