I agree with your findings. At one time, one headlight of my car failed. Since it has two headlights, I did not make much hurry to replace it, but 2 days later the other one failed. Then I was left in almost complete darkness. A SPOF is a SPOF and is subject to Murphy's law, which means it will hit you at the most inconvenient momemt.
The TS7740 has several selection criteria for physical tape reclaims: one is the period a tape has not been mounted. The max period you can set here was 365 days (or not do it at all). There must be a good reason to limit this period to 1 year, not more. Kees. -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Bill Ogden Sent: 08 July 2020 15:27 To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Storage & tape question Probably many others will chime in on this. I have lost RAID 5 arrays with two disk failures within an hour of each other. RAID is nice, but one must allow for failures. Long ago I was involved with reading archived tapes and transferring the data to CDs. The programs involved were home-written and the project ended up going nowhere. However, we discovered that tapes kept too long started having errors. (At that point, for the CD copy, we just logged the error and accepted the corrupt data; what else could we do?) How long is "too long"?? It was variable, but measured in a few years. The advice then was to minimally read the tapes every year or so to "retension" them. Don't know if this would apply to more modern tape media. (We also discovered that locally "burned" CDs are not expected last forever.) IMHO, the key point for tape backups are (1) off-site storage, (2) multiple PiT recovery, (3) logical error recovery. All this can be done with disk-only environments involving remote copy and lots of disk space, but all that becomes expensive for smaller shops. Bill Ogden ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
