[Maybe Spam] Re: very high i/o usage

Fri Jul 23 14:38:15 UTC 2004

Nir Cohen <NirC at bezeqint.co.il> wrote:
> Hi=20
> Sorry for not giving all the details .the os is Red Hat Linux 3.2.3-20
> with kernel  2.4.21-4.Elsmp
> Here is a top look:

>  15:06:50  up 82 days,  3:50,  1 user,  load average: 2.82, 2.92, 2.89
> 37 processes: 36 sleeping, 1 running, 0 zombie, 0 stopped
> CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
>            total   34.9%    0.0%    4.1%   0.3%     2.5%   39.0%   19.2%
>            cpu00   31.8%    0.0%    4.2%   0.6%     4.6%   41.8%   17.0%
>            cpu01   38.0%    0.0%    4.0%   0.0%     0.4%   36.2%   21.4%
> Mem:  1028524k av, 1012264k used,   16260k free,       0k shrd,   67064k
> buff
>                     816252k actv,   25244k in_d,   13988k in_c
> Swap: 2097096k av,  528776k used, 1568320k free                   14664k
> cached

>   PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME CPU
> COMMAND
>  7688 named     24   0  865M 743M  1364 S    38.1 74.0 867:53   1 named
>     8 root      15   0     0    0     0 SW    0.3  0.0 688:45   0 kscand
>   443 root      15   0     0    0     0 DW    0.2  0.0  12:14   0
> kjournald
>  1157 root      15   0   268  224   188 D     0.2  0.0   9:29   0
> syslogd
>     7 root      15   0     0    0     0 SW    0.1  0.0 120:36   1 kswapd
> 18464 nirc      15   0  1164 1124   912 R     0.1  0.1   0:00   1 top
>     1 root      15   0   136   96    80 S     0.0  0.0   1:38   0 init
>     2 root      RT   0     0    0     0 SW    0.0  0.0   0:00   0
> migration/0
>     3 root      RT   0     0    0     0 SW    0.0  0.0   0:00   1
> migration/1
>     4 root      15   0     0    0     0 SW    0.0  0.0   0:00   0
> keventd
>     5 root      34  19     0    0     0 SWN   0.0  0.0   0:00   0
> ksoftirqd/0
>     6 root      34  19     0    0     0 SWN   0.0  0.0   0:00   1
> ksoftirqd/1
>     9 root      25   0     0    0     0 SW    0.0  0.0   0:00   0
> bdflush

> The swap usage is all the time growing now its 528776k used but its all
> the time growing.

your named seems to have grown to a high value, if it's a 
resolving server for a large number of clients it might be reasonable,
in that case you needs more memory. 

If your named is one supplied from redhad i'd recomment you build
your own first.

> Regards

>                      Nir

>     Nir> Hello All I have a compaq G2 with 2xcpu 1.4Mhz and 2.0G ram
>     Nir> and a bind 9.2.3 installed .  The server is an authorized dns
>     Nir> for all our zones we have around 8000 zones(I work for Isp
>     Nir> company).  the problem I see on the server is that there is
>     Nir> very high i/o usage.  Befor I installed the 9.2.3 version I
>     Nir> had the 9.2.3rc4 and 9.3.0rc2 and 9.2.4rc4 versions which
>     Nir> worked good for one day and then The cpu usage bacome very
>     Nir> high it reched the 100% and I had to restart the server.  Now
>     Nir> the cpu not reached the 100% yest but the i/o is very high on
>     Nir> both cpu's.  Is it a bind problem ?or maybe hardware problem?

> It's impossible to answer this question from the info you've provided
> above. You didn't even say what OS you're running. You could start by
> telling us what process(es) were responsible for the very high amounts
> of disk I/O -- define "very high" -- and CPU utilisation. A system call
> trace on these processes might be helpful too.

> BIND is very highly unlikely to be I/O bound. Most of the time it will
> only be going to disk when loading zone files or writing log entries.
> Neither of these things is likely to mean lots of disk I/O. A name
> server isn't going to be CPU bound either unless it's getting thousands
> of queries per second and/or it's validating DNSSEC-signed replies.

> So what this means is your problem is almost certainly nothing to do
> with BIND. A mailing list or newsgroup for your OS may be a better forum
> for you to ask for assistance.

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-- 
Peter Håkanson         
        IPSec  Sverige      ( At Gothenburg Riverside )
           Sorry about my e-mail address, but i'm trying to keep spam out,
	   remove "icke-reklam" if you feel for mailing me. Thanx.