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 [email protected] Academic Computing & Communications Center ======I have not lost my mind -- it is backed up on tape somewhere.=====
