Why is it a pain to write "lots" of virtual tapes. I turned all stacking off and defined x1-99999 in my tape pools when we moved away from cartridges. Never looked back
> -----Original Message----- > From: IBM Mainframe Discussion List <[email protected]> On > Behalf Of Brian Westerman > Sent: Saturday, May 19, 2018 2:52 AM > To: [email protected] > Subject: Re: VTL as 3490 vs 3590 > > 3590's are "easier" to deal with if you use HSM at all, 3490's have to be set > up > as a percentage of the 3490 capacity, (otherwise you get something like > 800MB tapes (to HSM). While the VTS could care less, it is a pain to have > HSM writing 600 tapes a day. > > Several sites (about 1/3) we support are using VTL's as 3490's but most are > defined as 3590's. The actual numbers are (out of 117 sites with VTL's) 36 > are > defined as 3490's although almost all of them use a larger tape "size" (some > (most) are 2GB some or 5GB and a couple have no limit), whereas the rest of > them (81 sites) are defined as 3590's. > > Speed-wise, I don't think there is a difference, at least not that I can tell. > > Different VTL vendors seem to use different compression techniques so the > sizes vary as to how much actually fits on a tape dataset after compression > before it wants to load the next tape. > > I don't agree (but no one cares) with the sites that don't specify a limit to > the > tape size. I think that's just asking for a problem somewhere down the line, > but if that's what the client wants, we will run that way. > > If left to my own preferences, I would choose 3590 every time. I also like > those VTL's that don't keep the tape/disk storage inside the device and use > NetApp or something similar or like EMC does where the DASD is logically > pretty separate. Again, that's just a personal preference thing. > > Brian > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
