Just thought I'd bring up a point people might overlook. When I first explored the subject, IBM's recommendation was not to put HSM migrated files into the VTS. The rationale says that on native drives, HSM retrievals are done using "Note & Point" to the cartridge location of the file.
When I got to my represent job, they indeed put HSM into the VTS. The VTS virtual drive is defined as a 3490E. The effect of this is when there is a HSM recall, the entire contents of the IBM 3490E is transferred back to the VTS disk before the recalled file within the HSM file can be recovered. The result is much longer recall times than native drives. If one does not have very many recalls, this is no problem. Also it depends on the size of the VTS disk space and to how many HSM 3490E files, for many recalls, you can get onto it before it must erase other things or maybe have to halt things and destage new output work. Then we get into shuffling of HSM files around on the virtual cartridges and also the VTS shuffling files around to balance VTS cartridges. Luckily we do not do many recalls for we have enough DASD to keep things on resident. If it was my choice I would keep HSM migrated files on native drives and because of the way HSM does his collection along the way, those drives are kept well utilized. Of course this depends how often you tell HSM to go out and do its housekeeping. HSM migrated files in the VTS seems not to impact our processing so I am not going to change until it becomes a problem. Jim Marshall ---------------------------------------------------------------------- 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
