[Linux-cluster] GFS performance issue on CentOS 5.5

[Fred Wittekind]

 On 7/23/2010 1:40 PM, Gordan Bobic wrote:
> Fred Wittekind wrote:
>>  I do have noatime, need to add nodiratime.
>
> noatime is a superset of nodiratime.
Thanks, that's good to know.
>
>> There are PHP session files
>> on the gfs2 volume.  There used to be Zend Cache file on it, but I moved
>> those to tmpfs.  There is one other set of cache files that where put in
>> a bad directory, so they are hard to move to tmpfs without changing the
>> client's website code (although I may do this anyways).
>
> Indeed you may, that sounds like a good place to start looking for
> your performance problems.
I will try this.
>
>> I had considered moving the PHP session files to a memcache server, but
>> then I observed very long load times on static website content
>> (images).  Since images don't involve the session files, I had decided
>> that it looked like there was more of a problem than the session
>> files. Although, could lock issues with the session files effect load
>> times of
>> files in a completely different area of the directory tree?
>
> Session files will be accessed for ever page hit, will they not?
No.  PHP session files are only hit when accessing a PHP page that does
a session_start call.  So, if for instance you load a jpg file (that is
not served by a php script), there is no session file access.
>
> Gordan
>
> -- 
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster
>