Hi, All volumes here are 3390-9 10017 cylinders or the vast majority 3390-27 (LVS) 32760 cylinders. I think the choice to use high capacity tape more than Large Volume Support impacts the time to recover a single file though they do go hand in hand often. We want all the economy of scale we can get when provisioning space and especially when spooling data to a real media that is in a robot perhaps going offsite. Yes this means we 'waste' 99% of the space on a few 3390-9 volumes that have one of only a handful of data sets with very strict isolation requirements but the cost/risk of juggling small volume sizes in our configuration and recovery configuration is justification. Maybe someday "storage tank" will be a reality for MVS.
1. Point In Time FlashCopy takes seconds. Backup of FlashCopy target volume to high capacity 3592 tape much longer but does that matter? 2. Tape once job is complete and the FlashCopy withdrawn 3. Here application or HSM backups are used for more file recoveries than full volume backups. The Storage team makes it clear full volume backups taken during disaster recovery syncpoint are for DR not application convenience. They will recover a file but usually you don't have someone sitting around waiting for it since the latest full volume backup tapes go offsite hours after having been written out. HRECOVER self service is encouraged for users. A little tough love goes a long way in cutting down the amount of time your enterprise storage team spends doing individual file restores for folks. Best Regards, Sam Knutson, GEICO System z Performance and Availability Management mailto:[EMAIL PROTECTED] (office) 301.986.3574 "Think big, act bold, start simple, grow fast..." -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Skip Robinson Sent: Friday, February 08, 2008 12:28 PM To: [email protected] Subject: Re: VTOC size The idea of massive volumes is intriguing, but my concern would be backup/restore. On some our non-z platforms we have huge volumes many times the size of 3390-3. When one of them went south a while back, it took hours and hours to get it restored. With RAID arrays, of course, that's not supposed to happen; I think it was a problem with an SVC. On the mainframe we take frequent full volume backups. The likelihood of true failover (DR) is minuscule, and we use XRC mirroring for that contingency anyway. On the other hand the probability of having to retrieve an accidentally deleted or modified file is huge--it happens all the time even for sysprog finger checks. 1. How long does it take to make a tape backup of a 32760 cylinder volume? 2. Where does that backup live? 3. How long does it take to restore a critical 10 track file from two weeks ago that happens to live on the corner of cylinder 31753? . . JO.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 626-302-7535 Office 323-715-0595 Mobile [EMAIL PROTECTED] ==================== This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. ---------------------------------------------------------------------- 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
