Re: [Dazuko-help] CLAMD CPU usage.

[John Ogness]

On 2010-01-09, John Ogness <address@hidden> wrote:
>> I have a problem when running clamd in my Cent OS system, the CPU
>> usage suddenly rises to 90% for clamd when any operation (even
>> opening a manual page) is done and makes the system to a poor slow
>> state.
>>
>> Why these sudden peeks happen? Better if somebody briefs up why
>> this happen as I don't have any clue!!
>
>
> In order to help you, we need to know what you are using:
>
> - What version of Dazuko(FS)?
> - What version of ClamAV?
>
>> Is there any way to avoid this sudden peek of clamd usage!!
>
> If you are using DazukoFS you can use the "showfiles" utility
> (included in the DazukoFS source package) to see what files are
> being scanned when you do things like opening a man page. This might
> shed some light as to why clamd is taking so long. (Scanning those
> same files without DazukoFS should also take just as long.)

I just ran some quick tests using:

$ ./clamd --version
ClamAV devel-20100110/10277/Sat Jan  9 23:45:07 2010

with DazukoFS 3.1.3-rc1. I have DazukoFS covering all directories on
my system except for the temp directory for ClamAV.

Starting Firefox on my system normally takes 3 seconds. With ClamAV
running, it takes 54 seconds.

ClamAV appears to be quite slow. You can see that it takes multiple
seconds for many files that is scans. To help speed things up, I
turned off archive scanning. (54 seconds was the fast time.)

The performance issues you are experiencing exist because ClamAV is
very CPU-intensive and slow. If ClamAV were to implement scan result
caching, that would improve the performance considerably.

You may want to address your concerns on the ClamAV mailing list.

John Ogness

-- 
Dazuko Maintainer