Disk top usage PIDs

[Eduardo Meyer]

On Tue, Nov 4, 2008 at 12:27 PM, Eduardo Meyer <dudu.meyer at gmail.com> wrote:
> On Tue, Nov 4, 2008 at 12:18 PM, Bill Moran <wmoran at potentialtech.com> wrote:
>> In response to "Eduardo Meyer" <dudu.meyer at 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 at gmail.com
profissional: ddm.farmaciap at saude.gov.br