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