On 24 Dec 2021 at 12:11, George N. White III wrote: From: "George N. White III" <gnwiii@xxxxxxxxx> Date sent: Fri, 24 Dec 2021 12:11:03 -0400 Subject: Re: The definitive guide to replacing a disk in raid1? To: Community support for Fedora users <users@xxxxxxxxxxxxxxxxxxxxxxx> Send reply to: Community support for Fedora users <users@xxxxxxxxxxxxxxxxxxxxxxx> > > On Fri, 24 Dec 2021 at 10:50, Tom Horsley <horsley1953@xxxxxxxxx> wrote: > On Fri, 24 Dec 2021 15:38:05 +0100 > cen wrote: > > > I recently had to replace a bad disk in raid1 array and > finding proper > > docs was not a good experience. > > I've always noticed that about raid in general. Thousands > of internet > pages telling you how redundant arrays protect you from > disk failures > and you ought to use them. Nothing at all saying what > you do when > one of those disks fail :-). > > Though I have heard the claim that all you have to do is > swap in > a new blank disk and power up the system and magic > happens. > > That was certainly the case for external RAID boxes. Some could > hot-swap a failed drive. Back when a 10G SCSI drive was a big as > you could get, we used an external RAID with two live spares. > When a drive failed, a spare came up without manual intervention. > You could then replace the failed drive while the RAID was powered > up. The only failure I recall was when the host system SCSI controller > died. Remember way way back. Had a Novell 4.x server that had a duplex raid (mirror) system with 2 1G System disk and 4 - 9G (At time largest disk). Had two SCSI controllers with one of each drives in mirror to allow for disk or controller failures. Was a cool setup, but in pre-testing found an issue. The Primary System disk had a small DOS boot partition that was not mirrored to the other System disk. So if your primary system disk would fail the computer would continue to run off the secondary, but if you rebooted it would fail. Was an easy process to manually copy the partition to the other disk, and then one could swap positions. Otherwise it was great. Ran 10 computer labs off a Novell 4.x server with 350Mhz AMDK6-2 with 6 SCSI disks with 192M of Ram.. Never had a drive fail over many years. Did have our Admin have a System that was running SCO and it had a failure in a 3 disk system. It kept working fine after failure, but when they replace the bad drive the rebuild that was suppose to be automatic failed. Some how it mixed up which drive to rebuild and corrupted the whole raid. (Could have been operator error, but that is what they said happened?). Fortunately they did have a back right before they did the replacement, so just a couple days of down time. But know many never test that the system works or how to do the restores, and just hope it works. I like to also do bare metal backups just to be sure. Running one right now on my only windows 10 machines to one of my 5 Fedora machines. Best of luck to everyone. Unfortuantely, drives fail, and often don't give warnings. But prices are less expensive. Recall the 9G SCSI drives where like $450 each. My first computer had an option for a 20M Seagate ST-225, but it was a $2,000 option in 1983, so got my Heathkit H-120 Dual CPU system 8088/8080 with dual 320K floppies and 768K of Ram (more ram than IBM PC). Loved that machine 8Mhz CPU. Merry Christmas to those that celebrate it, and Best Wishes to others. > > -- > George N. White III > _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
