Re: linux /proc/sys/vm/pagecache for oracle

On Mon, 03 Apr 2006 23:06:17 +0200, Fabrizio Magni <fabrizio.magni_at_mycontinent.com> wrote:

>> Does anyone know what this parameter has been replaced with on RedHat
>> 4.0?
>>
>> I just noticed over 10G of my memory is used for file system caching.
>>
>> [root_at_mars ~]# more /proc/meminfo
>> MemTotal: 16032636 kB
>> MemFree: 4643788 kB
>> Buffers: 156844 kB
>> Cached: 10390004 kB
>> SwapCached: 24 kB
>> Active: 2662108 kB
>> Inactive: 8228036 kB
>> HighTotal: 0 kB
>> HighFree: 0 kB
>> LowTotal: 16032636 kB
>> LowFree: 4643788 kB
>> SwapTotal: 8385920 kB
>> SwapFree: 8385892 kB
>> Dirty: 64 kB
>> Writeback: 0 kB
>> Mapped: 2274900 kB
>> Slab: 123408 kB
>> Committed_AS: 12578340 kB
>> PageTables: 213160 kB
>> VmallocTotal:536870911 kB
>> VmallocUsed: 109584 kB
>> VmallocChunk:536760867 kB
>> HugePages_Total: 0
>> HugePages_Free: 0
>> Hugepagesize: 2048 kB
>>
>> # sysctl -w vm.pagecache="1 15 80"
>> error: 'vm.pagecache' is an unknown key
>>
>> # cat /proc/vmstat | grep nr_mapped
>> nr_mapped 568747
>>
>
>In general, on any 2.6 kernel (not only redhat), you should use
>/proc/sys/vm/swappiness.
>

This looks to be a parameter affecting swapping processes, not file system caching.

Anyway, my 'cached' file systems seem to be not the ones oracle is sitting on, as when I remounted in 'direct' cache didn't go away. The fie system is vxfs and we are using ODM, so nothing should be cached.. which is why I was confused that cache is so big. .......
We run Oracle 9.2.0.6 on RH4 AMD
remove NSPAM to email Received on Wed Apr 05 2006 - 13:36:24 CDT