On 03/23/2010 05:29 PM, Pinnacle wrote: > Anybody read the Mainframe Executive article on the death of tape as a > backup media? The guy writing it used to work for STK and Sun, and now > works for disk-based backup vendors. He says the following: > > - 15% of all backups fail (my experience < 1%) > - 10-50% of all restores from tape fail (my experience <1%) > - 40-50% failure when restoring data from tape > 5 years (my experience > again is <1%) > > So what are you guys seeing out there? Do we really have mainframe tape > failure rates in the double-digits percentwise? If we do, then the guy > is right and tape is dead, but I just don't buy those figures. What say > you? > > Regards, > Tom Conley
I can only conclude the author is totally ignorant of mainframe 3490, 3590, or later tape technology. Old reel-to-reel technology was getting very marginal when we finally got rid of our last drives - partly because you couldn't get any new media. We once had problems with 3480 cart reliability because we inherited some media from another company that hadn't properly maintained their library and the bad media constantly contaminated the drive heads. Once we realized what was happening and got rid of the bad carts, reliability went back to the usual < 1% failures. We back up over 300 DASD volumes to 24 3590 carts every night, have never had an undetected write problem, and those at worst are one or two files of the 9,000+ created by this process during the month, and are corrected on the spot by restarting the job to new media for subsequent files. We have never had a problem reading one of those backups. Because of the large amount of data on one 3590, we do duplex much of the archival stuff on 3590s, because there is always the chance of accidental physical damage to a cart by either an Operator or a berserk tape drive. We rebuild a damaged 3590 cart maybe once every 6 months. -- Joel C. Ewing, Fort Smith, AR jremoveccapsew...@acm.org ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
