[cisco-voip] high I/O Wait on one core

[Erick Wellnitz]

8.0.3.20000-2


On Fri, Apr 5, 2013 at 11:40 AM, Haas, Neal <nhaas at co.fresno.ca.us> wrote:

>  What version are you? 7 or 8****
>
> ** **
>
> ** **
>
> Neal Haas****
>
> ** **
>
> *From:* cisco-voip-bounces at puck.nether.net [mailto:
> cisco-voip-bounces at puck.nether.net] *On Behalf Of *Wes Sisk
> *Sent:* Friday, April 05, 2013 9:09 AM
> *To:* Erick Wellnitz
> *Cc:* cisco-voip
> *Subject:* Re: [cisco-voip] high I/O Wait on one core****
>
> ** **
>
> cmoninit is one of the informix database processes. There are are several
> processes that each do different roles. it's not simple to identify the
> exact role of a specific oninit process.****
>
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>
> <quote>****
>
> Looks like each of the oninit processes implements a different (or
> parallel or redundant) part of the overall database server:
>
> -bash-3.2$ onstat -g sch
>
> IBM Informix Dynamic Server Version 11.50.UC8X6   -- On-Line -- Up 3 days
> 16:22:33 -- 230984 Kbytes
>
> VP Scheduler Statistics:
> vp    pid       class       semops    busy waits  spins/wait
> 1     24024     cpu         15202292  0           15205721
> 2     24066     adm         0         0           0
> 3     24067     LIC         18        0           18
> 4     24068     DBFNC       1         0           1
> 5     24069     lio         136050    0           0
> 6     24070     pio         1287      0           0
> 7     24071     aio         903428    0           0
> ...
>
> http://publib.boulder.ibm.com/infocenter/idshelp/v117/index.jsp****
>
> </quote>****
>
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>
> Generally, yes, you're looking at something in the database generating
> lots of churn. THis could be CDRs, it could be CAR, it could also be AXL or
> high rate of change notifications.****
>
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>
> Looks like you would benefit from something like this:****
>
> CLI show tech activesql****
>
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>
> from:****
>
> CSCsz67357    Need an Informix profiler built into CLI ****
>
> ** **
>
> Regards,****
>
> Wes****
>
> ** **
>
> On Apr 5, 2013, at 11:20 AM, Erick Wellnitz <ewellnitzvoip at gmail.com>
> wrote:****
>
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>
> caroninit seems to be the biggest offender (by about 50x) in both disk
> writes and cpu usage.  Am I correct in assuming this has something to do
> with call detail records?****
>
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>
> On Fri, Apr 5, 2013 at 9:02 AM, Tom Piscitell (tpiscite) <
> tpiscite at cisco.com> wrote:****
>
> Erick,
>
> You can use the FIOR utility from the CLI to identify which processes are
> writing to the disk.
>
> admin:utils fior
>       utils fior disable
>       utils fior enable
>       utils fior list
>       utils fior start
>       utils fior status
>       utils fior stop
>       utils fior top
>
> Here is a typical use case:
>
> 1. Enable the FIOR utility before/during a time of High IO Wait
>         admin:utils fior enable
>         File I/O Statistics has been enabled.
>         admin:utils fior start
>         Loading fiostats module: ok
>         Enabling fiostats : ok
>         File I/O Statistics has been started.
>
> 2. Wait a couple minutes. FIOR will poll for data every 5 seconds I
> believe. Then use utils fior top to see whats hitting the CPU the hardest:
>
> admin:utils fior top ?
> Syntax:
> utils fior top n sort_by [start=date-time] [stop=date-time]
>
>          n:            number of processes
>          sort_by:      read, write, read-rate, write-rate
>          date-time:    of the form %H:%M, %H:%M:%S
>                                    %a,%H:%M, %a,%H:%M:%S
>                                    %Y-%m-%d,%H:%M, %Y-%m-%d %H:%M:%S
> Example:
> admin:utils fior top 10 write start=2010-04-20 10:00:00 stop=2010-04-20
> 10:30:00
>
> This of course won't tell you *why* a process is hitting the disk, but it
> will at least show you who has the most read/writes. To answer the why
> question you would need to look at traces for the offending process/service.
>
> HTH,
> -Tom
>
> On Apr 4, 2013, at 5:43 PM, Erick Wellnitz <ewellnitzvoip at gmail.com>
> wrote:
>
> > Hello all!
> >
> > I have a dual 4 core IBM 7835I3 which is my publisher.   One one core of
> the first CPU the I/O Wait is through the roof.  RTMT shows that writes to
> the hard drives are at between 600 and 700 MB/s which is exponentially
> higher than the subscriber on the same model of hardware.
> >
> > Short of calling TAC is there any way to figure out what is causing the
> extremely high volume of writes to the drives?  I already stopped most
> traces and looking at the processes doesn't give any clues.
> >
> > Thanks again!
> >
> >
> > _______________________________________________
> > cisco-voip mailing list
> > cisco-voip at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-voip****
>
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>
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