** steve-ALUG@hst.me.uk steve-ALUG@hst.me.uk [2017-12-20 21:31]:
On 20/12/17 17:26, Mark Rogers wrote: {SNIP GOOD COMMENTS}
Good point that I hadn't considered about a backup only existing in one place & raid-ing a backup drive. I have 3 separate backup systems of various quality, unfortunately 2 share one unraided backup drive! The third is "sneakernet" USBdrive backup.
** end quote [steve-ALUG@hst.me.uk]
To emphasise the fact that RAID is not a backup I tend to use two situations I've been involved with. One is a Linux server that had software RAID on and had both drives fail together.
The other goes back further, to my NT sysadmin days. We had a Compaq server in San Jose that had a drive fail in the hardware RAID setup. There was another drive giving warnings so we called the Compaq engineer in to sort things out. We had some non-technical staff on site, but were monitoring things from here. It started well as he removed the failed drive and inserted the new one. We told him we would let him know when the RAID had finished recovering so he could swap the second drive (this was RAID 5 iirc). After a while our monitor threw up multiple warnings and we got in touch to find out what was happening. It turned out the engineer had noted that the lights had stopped flashing so had decided to swap the second drive. Unfortunately the RAID hadn't finished recovering so the whole server, OS, data, the lot was corrupted. We sent the engineer away, got one of our IT staff on site and rebuilt the server from the backups - and never let a Compaq engineer near our kit again!