Thanks you
On Mon, Jul 12, 2010 at 6:09 AM, J. Pohlmann <jpohlm...@shaw.ca> wrote: > In many installations it's a close to meaningless number. For empty tapes, > it's the estimated capacity of the tape multiplied by maxscratch. Then as > tapes become full, the actual number of bytes written will modify the > estimated capacity value. The actual bytes written depends on > compressibility of the data. The reason why in most of my installations it > is a meaningless number is that tape libraries are managed by the number of > scratch tapes available. I generally suggest that there should be about 10% > scratch tapes in a tape library or at least five (five is also the > threshold > value for attention grabbers in the TSM v5 Operational Reporting Facility). > Tape storage pools are then not restricted by the number of scratch tapes > that may be assigned. Very often maxscratch is set to 10000 or some such > number. You will often find large maxscratch values also in > server-to-server > virtual volume environments where the maximum capacity in most cases is set > to be significantly smaller than the capacity of, for example LTO3 or LTO4 > tapes. > > Note that for device class disk storage pools the estimated capacity is the > actual capacity. > > Joerg Pohlmann > 250-585-3711 > > -----Original Message----- > From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of > Mehdi Salehi > Sent: Friday, July 09, 2010 08:06 > To: ADSM-L@VM.MARIST.EDU > Subject: [ADSM-L] tape stg capacity > > Hi, > How is tape storage pool "estimated capacity" calculated? I see different > values for similar storage pools of the same devclass and maxscratch. > > Thanks >