Re: vm issues on sap app server

From: Dejan Muhamedagic (dejan@hello-penguin.com)
Date: Thu Feb 20 2003 - 07:48:33 EST


Rik,

On Wed, Feb 19, 2003 at 08:08:01PM -0300, Rik van Riel wrote:
> On Wed, 19 Feb 2003, Dejan Muhamedagic wrote:
>
> > cache. Is it possible to reduce the amount of memory used
> > for cache?
>
> Yes, you can reduce the size of the cache above which the
> pageout code will only reclaim cache and not application
> data. To set the percentage to 10% (from the default 5%):
>
> echo 1 10 > /proc/sys/vm/pagecache

Will that work with rmap15d? The code seems to support only min
and borrow parameters. Correct me if I'm wrong. This is what it
looks like currently:

# cat /proc/sys/vm/pagecache
1 3 20
# mem | grep Cache
Cached: 4569128 kB
SwapCached: 829668 kB
ActiveCache: 136728 kB

>
> > Finally, there's a third SAP app server, an RS6000 running
> > AIX with the same amount of memory, which seems to be more
> > stable under various loads.
>
> In that case you're probably familiar with the cache size
> tuning, since AIX has the exact same tuning knob as rmap ;)

AIX vmtune -P is equivalent to the Linux cache-max, but cache-max
is not implemented.

Cheers!

Dejan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sun Feb 23 2003 - 22:00:29 EST