Regarding the second disk failing while the first was rebuilding, I've heard more than once that a second failure in a RAID array shortly after the first, while the rebuild is happening is not that uncommon. Something about the sudden extra stress on the rest of the drives in the RAID set due to their ultra high utilization trying to get the failed drive rebuilt. Has anybody else heard this? Is there documented validity to this assertion?
Rex -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of John McKown Sent: Tuesday, July 7, 2020 8:58 AM To: [email protected] Subject: [External] Re: Storage & tape question <snipped to the relevant portions for my question> We had a similar problem occurs, long ago, with an actual SAN dasd array (for Windows, not MVS). Weekend backup to physical tape aborted on a Sunday. The Windows admin said "No problem, it's a RAID-5 array, I can fix it Monday morning." A few hours later, a disk in the array failed. No problem, right? Unfortunately, while the CE was on his way in to replace it, a second disk failed. The array was destroyed. Management said to repair it and reload from the Sunday backup and we'd be good. When the admin admitted that the backup failed and he didn't go in, he was immediately terminated. ***** Now, what are the chances that 2 drives in an array will fail within hours? I don't know, but one thing many don't think about with a "new array" is that all the drives are likely the same age and will start to fail (if they are) about the same time. ***** The information contained in this message is confidential, protected from disclosure and may be legally privileged. If the reader of this message is not the intended recipient or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, distribution, copying, or any action taken or action omitted in reliance on it, is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by replying to this message and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
