Roger,

I'll defer to an IBM answer, but my read is "no", they aren't recommending DISK 
over FILE.  I think what they are saying is no more along these lines:  IFF you 
are using DISK storage pools, they will perform better on Raw LV than on cooked 
JFS2.  This is a change from the past, where they had stated a preference for 
JFS2 over RAW.

I do not think they are stating a preference for DISK over FILE.

my 2 cents.
..Paul

At 04:27 PM 8/6/2010, Roger Deschner wrote:
>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.=====


--
Paul Zarnowski                            Ph: 607-255-4757
Manager, Storage Services                 Fx: 607-255-8521
719 Rhodes Hall, Ithaca, NY 14853-3801    Em: psz1 AT cornell DOT edu