[Clamav-devel] Slow scan when load average increase

[Micah Snyder (micasnyd)]

Hello Enrico!

Thanks for asking.  We do not currently have benchmark statistics for ClamAV, although research into benchmarks, minimum system requirements, etc are in the pipeline for future versions of ClamAV.

I am unsure what you mean by “load average at 3”.  Do you mean like “stress -c 3”?  Regardless, it is no surprise to me that if your machine is under heavy load, ClamAV will take longer to scan your files.  ClamAV is relatively processor intensive and would likely take longer if it has to context switch frequently to compete with another process.

I do not believe that the mailing list forwarded the strace attachment.  If the performance under load is causing an issue for you, feel free to open a bug report on https://bugzilla.clamav.net/ and attach the strace to the bug report.

Regards,
Micah

Micah Snyder
Software Engineer
Talos Intelligence
Cisco Systems, Inc.

On Sep 8, 2017, at 12:07 PM, Enrico Bianchi <enrico.bianchi at live.com<mailto:enrico.bianchi at live.com>> wrote:

I have a strange problem. With ClamAV 0.99.2 and latest database
version, when I scan a big email, performance decrease when I have an
small load average increase. For example, with a 25Mb email, in a
virtual machine with 2Gb of RAM, 4 cores and load average at 0, clamscan
terminate in 46 seconds. With load average at 3 (for simulating an high
load average, I've used the stress command), clamscan terminate in 2
minutes. Is normal? I've tested this behaviour in Linux (virtual and
phisical) and in FreeBSD. I've also attached a strace of the clamscan
(please, note that I have the same problem with clamd)

Cheers,
Enrico


_______________________________________________
http://lurker.clamav.net/list/clamav-devel.html
Please submit your patches to our Bugzilla: http://bugs.clamav.net

http://www.clamav.net/contact.html#ml