Topic: Server caving in - from what?

[holger]

Hi
I've been running my Via C3 server now for quite a while.
-----------------------------------
CPU: Centaur VIA Nehemiah stepping 0a
-----------------------------------

For the last half year or so it's been caving in on a regular basis - approx once or twice a month. It may be from spam bombs.

load will go way up to 15-20 or more:
-----------------------------------
top - 22:34:45 up 3 days,  3:59,  1 user,  load average: 17.19, 13.59, 11.43
Tasks: 217 total,   1 running, 216 sleeping,   0 stopped,   0 zombie
Cpu(s):  1.6% us,  1.3% sy,  0.0% ni,  0.0% id, 97.0% wa,  0.0% hi,  0.0% si
Mem:    191004k total,   185896k used,     5108k free,      980k buffers
Swap:  2386808k total,   524084k used,  1862724k free,    20276k cached

  PID USER      PR  NI %CPU    TIME+  %MEM  VIRT  RES  SHR S COMMAND
 1629 root      16   0  1.3   0:06.89  0.5  2648 1004  696 R top
 1767 stunnel   18   0  0.7   0:00.02  0.7  4496 1336 1064 S stunnel-tls
 1772 stunnel   19   0  0.3   0:00.01  0.7  4532 1336 1064 S stunnel-tls
-----------------------------------

Two spam processes will start consuming loads of mem:
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1877 spamd     16   0  0.0   0:01.63 15.2 53764  28m 2092 S spamd
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And as can be seen above the server will be 97% or so "waiting". Can't figure out what it is "waiting" for though!?

It will stop serving http, imap, smtp and smb - and ssh will be hard/slow to establish.

Suggestions for how to diagnose the problem - or even better solve it - are welcome.

Thank you.

[byte]

I'd add more memory (RAM) go at least 512Mb if you can, specifically as you have spamassassin running as well.

[holger]

I'd add more memory (RAM) go at least 512Mb if you can, specifically as you have spamassassin running as well.

Thanks for your reply.

So you think it's the evil swap death - and the only real solution is to just add more RAM?
 

[CharlieBrady]

Thanks for your reply.

So you think it's the evil swap death - and the only real solution is to just add more RAM?
 

Yes. The 'waiting' is waiting for disk, to swap stuff in and out. Look at how much swap space is being used. Ideally no swap will be used.

[mmccarn]

I had similar issues that were eliminated by upgrading from 256MB to 512MB.

[holger]

Hmm - my old 6.5 server had no problems running on 128M. But then spamming was nowhere near as heavy.

Well, thanks again. I've ordered 1G just to be on the safe side. Will report back...

[raem]

holger

You obviously have insufficient RAM, but you may also experience overload issues caused by spam processing. If you do not have RBL lists enabled see these tips
http://forums.contribs.org/index.php?topic=39639.0

[holger]

Thanks,

I think I've already followed those:
http://wiki.contribs.org/Email

Code: [Select]

# config show qpsmtpd
qpsmtpd=service
    Bcc=disabled
    BccMode=cc
    BccUser=maillog
    DNSBL=enabled
    LogLevel=8
    MaxScannerSize=25000000
    RBLList=zen.spamhaus.org:whois.rfc-ignorant.org:dnsbl.njabl.org
    RHSBL=enabled
    RequireResolvableFromHost=no
    SBLList=dsn.rfc-ignorant.org
    access=public
    status=enabled

And

Code: [Select]

# config print spamassassin
spamassassin=service|DNSAvailable|yes|MessageRetentionTime|90|OkLanguages|all|OkLocales|all|RejectLevel|12| (...linebreak...)
ReportSafe|0|Sensitivity|custom|SkipRBLChecks|0|SortSpam|enabled|Subject|[SPAM]|SubjectTag|enabled|TagLevel|4|UseBayes|1|status|enabled


[holger]

Just for the record. 1G RAM did the trick.
Everything is snappier, especially webmail which used to be dead slow and the system load is generally way lower than what it used to be.

Thanks and cheers