It would probably not be a problem with it working, but with the two
lun's concatenated, there is probably little to no chance DB2 will be
able spread the I/O out among the 2 lun's.  If it's in a separate
filesystem, DB2 will spread the data out across them.  It will be even
worse with 3, 4, 5, or more lun's.

On Tue, May 11, 2010 at 3:21 PM, John D. Schneider
<john.schneider AT computercoachingcommunity DOT com> wrote:
> Greetings,
>   I have a customer running TSM 6.1.3 on a Linux RedHat 5.4 server.
> They are using high-performance SAN attached disk for the TSM database
> and logs.  They have created the TSM database all in one directory under
> one filesystem.  Recently then needed to add more space, and they carved
> out a lun from another RAID group, and then added that lun to the
> existing filesystem.  TSM shows that it now has the additional space,
> but it is still all under one directory.
>   In reading the Performance Guide and Admin Guide, they both recommend
> spreading the data out over multiple directories, putting each directory
> behind separate disks/luns.  This certainly makes sense to spread the
> I/O out over multiple luns, and I get that.  But is there anything wrong
> with the way my customer has done it?  They are using multiple luns from
> different RAID groups, but they are all put together behind one
> directory.  Is this going to become a problem as they add more and more
> load to this instance?  If TSM has lots of separate directories and they
> are across multiple luns, does TSM do it's database I/O differently?
>
> Best Regards,
>
> John D. Schneider
> The Computer Coaching Community, LLC
> Cell: (314) 750-8721
>



-- 
Andy Carlson
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