On Tue, 18 Oct 2005 16:10:10 -0400, Habres, Richard (GTI) <[EMAIL PROTECTED]> wrote:
>The only problem with leaving it on ML1 is the CPU used to do the >compression. Tape compression is in the hardware. ML1 compression is in >the software. Not necessarily. We have ML2 on Flex-ES FakeTape(tm) and our release of Flex-ES does not support compression. Therefore I choose to do software compression on ML2. I hope HSM is smart enough to just copy compressed ML1 to compressed ML2 without doing expand/compress. But anyway, the CPU it expends is controlled by WLM so it is not a big issue. I did try using GZIP once the FakeTape file was created, but the CPU spike killed MVS because it was not under WLM. Not doing any compression at all uses a LOT of disk space which may be cheap, but is not in the budget. For us the trade-off is worth it, YMMV. New releases of Flex-ES do support compression on AWS tapes, but I have no experience of the CPU requirements or its effect on MVS. I suspect it may make it a non-starter for a Production shop. Dave ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
