I thought the food fight between sequential (devtype FILE) and random
(devtype DISK) primary storage pools had been settled a while ago in
favor of sequential. Indeed, TSM development has added features to make
sequential FILE stgpools quite a bit easier to deal with.

But now I am reading in "TSM 6.2 Performance Tuning Guide" that:
"Customer experience and measurements in the lab show that raw logical
volumes offer better client backup/restore throughput and server
administrative process performance." (You can only allocate devtype DISK
in raw logical volumes.) It also notes that the previous advantage of
read-ahead provided by some filesystems such as JFS2 is now incorporated
into many disk subsystems, so that is no longer a consideration.

So it would seem that if you aren't using TSM deduplication, the
Performance Tuning Guide now recommends that you should use random
instead of sequential primary 1st-level disk storage pools.

Am I reading this right?

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu
               Academic Computing & Communications Center
======I have not lost my mind -- it is backed up on tape somewhere.=====