Date: Tue, 4 Nov 2008 12:49:41 -0200 From: "Eduardo Meyer" <dudu.meyer@gmail.com> To: "Bill Moran" <wmoran@potentialtech.com> Cc: questions@freebsd.org Subject: Re: Disk top usage PIDs Message-ID: <d3ea75b30811040649i11e3a314ud35667ea193ce9a@mail.gmail.com> In-Reply-To: <d3ea75b30811040627h29a4c65tc25f04e1f28ea31@mail.gmail.com> References: <d3ea75b30811040612g3ba10a8fuf5551b730176acc2@mail.gmail.com> <20081104091801.ff0297b0.wmoran@potentialtech.com> <d3ea75b30811040627h29a4c65tc25f04e1f28ea31@mail.gmail.com>
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On Tue, Nov 4, 2008 at 12:27 PM, Eduardo Meyer <dudu.meyer@gmail.com> wrote:
> On Tue, Nov 4, 2008 at 12:18 PM, Bill Moran <wmoran@potentialtech.com> wrote:
>> In response to "Eduardo Meyer" <dudu.meyer@gmail.com>:
>>>
>>> I have some serious issue. Sometimes something happens and my disk
>>> usage performance find its limit quickly. I follow with gstat and
>>> iostat -xw1, and everything usually happens just fine, with %b around
>>> 20 and 0 to 1 pending i/o request. Suddely I get 30, 40 pending
>>> requests and %b is always on 100% (or more than this).
>>>
>>> fstat and lsof gives me no hint, because the type of programs as well
>>> as the amount of 'em is just the same.
>>>
>>> How can I find the PID which is hammering my disk? Is there an "iotop"
>>> or "disktop" tool or something alike?
>>
>> top -m io -o total
>
> Great, thats exactly what I was looking for, thank you a lot Mr Moran.
I see syncer (40%) and bufaemon (10%) and after that, imapd. The first
ones are kernel PIDs (36 and 37).
PID USERNAME VCSW IVCSW READ WRITE FAULT TOTAL PERCENT COMMAND
36 root 2 2 0 31 0 31 40.79% bufdaemon
37 root 2 2 0 16 0 16 21.05% syncer
71501 vmail 4 0 0 0 0 0 12.00% imapd
I guess it a symptom of some hardware problems, kernel itself is not
supposed to do this many I/O, right?
Sometimes PID 39, softdepflush, is always on top 3.
--
===========
Eduardo Meyer
pessoal: dudu.meyer@gmail.com
profissional: ddm.farmaciap@saude.gov.br
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