[Fedora-directory-users] Error Logging Performance

[David Boreham]

Roman RATHLER wrote:
> If I activate error logging for ACL Control Summary or similar, the 
> machine totaly goes into IO-Wait. It just writes maybe 100K/second but 
> is totaly unusable any more... From normal 1% CPU Load (on a 2 Way 
> Xeon) it moves to 200% CPU Utilization.
> Debugging ACLs therefore is nearly impossible on a productive system...
>
> We run the Fedora-DS 1.0.4 (fedora-ds-1.0.4-1.RHEL4) on an up2date 
> CentOS System... Is there any perfomance tuning option like with the 
> log-buffering for access log. I can't see, why logging kills the machine!
Errors often occur before a crash, and therefore the error log
is flushed to persistent store often in order to improve the chances
that any message emitted before a crash will be retained.

I seem to remember that buffering can be enabled on the error log
but I can't remember the details. Probably in the documentation 
somewhere though.
I think the underlying code is the same for the error log vs. the access log
(which is optimized for performance by default) , so it should be possible
to configure the error log to buffer.

Alternatively you could put the error log file on a ramdisk.