:>:-----Original Message----- :>:From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On :>:Behalf Of R.S. :>:Sent: Monday, January 23, 2012 12:46 AM :>:To: IBM-MAIN@bama.ua.edu :>:Subject: Re: DFHSM: Backup tape lost due to errors :>: :>:W dniu 2012-01-22 05:21, Joel C. Ewing pisze: :>:> I've said it before, but will say it again: modern tape media has such :>:a :>:> large capacity that a single dfhsm cartridge can contain an incredibly :>:> large number of datasets. It is almost inevitable that loss of a single :>:> dfhsm ML2 or Backup cartridge will impact something you care about or :>:> can't afford to lose (or are legally required to retain), and it is :>:also :>:> inevitable that single cartridges will occasionally be physically :>:> damaged. Over the long haul, you really can't afford NOT to duplex all :>:> dfhsm carts (and for that matter, non-dfhsm carts that contain data you :>:> can't afford to lose). :>: :>:90% Agreed, some remarks: :>:1. Cart capacity is not so relevant. The problem exists with any cart :>:capacity, the difference is in a likehood, but the likehood is quite :>:similar (same order of magnitude). :>:2. It worth to separate two cases: :>:a) Backup copy loss. It's more or less like loss of spare in a RAID :>:group, you did not lose your data, you lost redundancy. Additional event
What you have lost is the ability to restore the previous version of the data after discovering that the recent updates need to be backed out for whatever reason. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
