qmailtoaster-list  

[qmailtoaster] Re: Memory dan Email stats

Eric Shubert
Mon, 08 Feb 2010 07:34:44 -0800

PakOgah wrote:
Eric Shubert wrote:

Because of the way linux uses memory for caching files, it will look as though you don't have much free memory regardless of how much you have (linux uses what you give it, quite smartly). Use of swap is a better indicator of need for more ram, as is a small cache size. Using some swap on a toaster isn't necessarily a cause for concern.

I expect you probably don't need more ram. Are you using spamdyke? If not, you should be. It will reduce the load on your machine considerably. The biggest users of resources on QMT are spamassassin and clamav. Spamdyke rejects 80+% of spam before it's even transmitted, which means it's never scanned or delivered either. It's a huge savings.
yes you are correct, clamd and spamd are the top 5 processes which use most memory I have used spamdyke, and I see it on my machine it has many child processes,
and indeed it eliminate more spam.

Next biggest performance gain can be made by following Jake's video that puts simscan working files in a tmpfs (ram) rather than writing and reading them from disk. This shortens scanning time considerably and relieves contention on i/o.

Once you've done those 2 things, please report back your results. If your QMT is still under heavy load (BTW, what are your load figures typically like during the day?), then you'll need to look at some upscaling alternatives.

here's my top 5 processes at day

top - 13:22:21 up 5 days, 19:15,  1 user,  load average: 1.80, 1.72, 1.07
Tasks: 299 total,   1 running, 298 sleeping,   0 stopped,   0 zombie
Cpu(s): 0.5% us, 0.4% sy, 0.0% ni, 96.4% id, 2.6% wa, 0.0% hi, 0.1% si
Mem:   2056376k total,  2003780k used,    52596k free,   114848k buffers
Swap:  4192956k total,      144k used,  4192812k free,  1209316k cached

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
8446 clamav    16   0  294m 207m 1396 S    0 10.3  63:16.70 clamd
4508 vpopmail  16   0  121m  81m 2364 S    0  4.1   2:15.96 spamd
7688 vpopmail  16   0  112m  72m 2336 S    0  3.6   0:16.39 spamd
25971 root      16   0  101m  62m 2984 S    0  3.1   0:13.84 spamd
10562 apache    16   0  164m  23m 2396 S    0  1.2   0:03.22 httpd

---------------------------------------------------------------------------------

Have you applied Jake's change for the simscan working directory?

You don't need more ram. Your swap file is virtually unused, and there is 1.2G cached i/o. As your processes require more ram, linux will reduce the i/o cache to accommodate it. You have plenty of ram IMO.

As a side note, 4G of swap is overkill as you can see. Making swap 2x the amount of ram used to be the rule of thumb, but that's not as applicable these days with so much ram. In your system, I think I would use 1G of swap. If your system actually uses that much, performance will be suffering, and at that point you'll be wanting to add more ram.

So back to your performance issue. Your Cpu is not strained (96.4% idle), and not waiting a lot either (2.6%). That's good.

Your load is fairly high though, 1.0+ over the previous 15 minutes and trending upwards. This is puzzling to me. I've seen this sort of thing before, but only in a VM environment. This isn't a VM guest is it?

Do you have zombie processes running? Your cpu load is low, yet there are 3 spamd processes running.

Anyone else have any thoughts about this (slightly) high load?

--
-Eric 'shubes'


---------------------------------------------------------------------------------
Qmailtoaster is sponsored by Vickers Consulting Group 
(www.vickersconsulting.com)
   Vickers Consulting Group offers Qmailtoaster support and installations.
     If you need professional help with your setup, contact them today!
---------------------------------------------------------------------------------
    Please visit qmailtoaster.com for the latest news, updates, and packages.
To unsubscribe, e-mail: qmailtoaster-list-unsubscr...@qmailtoaster.com
    For additional commands, e-mail: qmailtoaster-list-h...@qmailtoaster.com