what is fsck's "slowdown"?
Marc G. Fournier
scrappy at hub.org
Fri Sep 3 20:33:37 PDT 2004
On Fri, 3 Sep 2004, Don Lewis wrote:
> On 3 Sep, Marc G. Fournier wrote:
>>
>> I'm running another fsck on a 4.x system ... I know 5.x brings in the
>> background mode for it, which would definitely make my life easier, *but*
>> ... when running fsck, it says its using up 99% of the CPU:
>>
>> # ps aux | grep fsck
>> root 67 99.0 5.0 184252 184284 p0 R+ 12:46PM 254:16.68 fsck -y /vm
>>
>> now, its a dual CPU system ... on an MP system, is it not possible to have
>> it parallelize on a file system, so that it makes use of all available
>> CPU?
>>
>> For instance, right now, its in Phase 4 ... on a file system where ctl-t
>> shows:
>>
>> load: 0.99 cmd: fsck 67 [running] 15192.26u 142.30s 99% 184284k
>> /dev/da0s1h: phase 4: cyl group 408 of 866 (47%)
>>
>> wouldn't it be possible, on a dual CPU system, to have group 434 and above
>> run on one process, while group 433 and below running on the second, in
>> parallel? Its not like the drives are being beat up:
>
> Would the file system in question happen to be full of UNREF files that
> fsck is deleting?
mostly 'ZERO LENGTH DIRECTORY' ...
----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org Yahoo!: yscrappy ICQ: 7615664
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