On Sat, 22 Dec 2018 06:27:28 -0600, Richard Owlett <[email protected]> wrote: > For years I've told others to have backups. > My primary machine just went to the shop which reminded me I should > be more organized and current myself. > > Any recommended survey articles?
Whenever the topic of backups comes up, I like to first clarify what exactly the goals are as there is no one size fits all. For a basic Windows/Mac home user, I might recommend something simple, but off-site like Carbonite, however, I don't think that's for this audience. The biggest issue is often hard drives dying, in particular, large spinning rust drives. The quick fix for that is using RAID. However, that doesn't protect from a rouge power supply killing all your hard drives. The next level is getting the data onto secondary storage on another system. That can be accomplished from a simple shell script to copy or rsync the files to the right place. However, there's still the case of a user accidentally deleting a file and not noticing for a week (or more) after a new sync has been done so it's better to keep multiple snapshots of the backup. At some point, you might have to consider what happens if there's a fire or other disaster and the need for off-site backup of the data. There's also metadata that might be important. System files might use ACLs or SELinux labels that need to be backed up as well, not to mention standard POSIX permissions. Disk images for virtual machines might be sparse and should be backed up as such so they don't bloat the backup needlessly filling it up with zeros. What scenarios are you trying to protect against? As two examples, my Personal MacBook Pro uses Time Machine over Wi-Fi (while I'm at home) to fully backup my laptop to a Linux server that acts like an "Apple Time Capsule". I also have iCloud linked for remote find/wipe. When my laptop was stolen, I was able to request a remote lock and wipe of my entire laptop through iCloud (the only reason I use iCloud) and restore my full install with all programs onto a fresh MacBook Pro I bought to replace my old one. The Time Machine software is very much Apple's implementation of exactly what Dirvish is with hard links for snapshots in the same vein. At work, we've used Dirvish as a full backup solution for about 15 years now with great success. In that time, we've had to do 3 completely bare-metal restores of the server. We originally started with 4 drives in a RAID 5 configuration. The first time we had a hard drive failure, I expected I had some time to plan for ordering a new drive and scheduling a server downtime. Well, about 2 weeks after the first drive died, a second drive failed bringing the server down completely. Part of the problem of RAID5 is that it had horrible performance in a degraded state and causes a lot more I/O. That and having all the drives from the same manufacturing lot just a few months past their warranty end date meant similar failure times. We ended up replacing all the drives and switching to a RAID10 plus 1 spare drive. RAID10 performs far better when one drive is down and it will rebuild immediately onto the spare drive, but only using one other drive for heavy I/O. While this has served far better since the switch, it didn't help the one time the power supply exploded and sent a surge down the SATA power lines killing all 5 drive controllers. After that event and with a fresh power supply, the computer did not even recognize hard drives as connected. Tried several other enclosures and a second computer, but no response from the drives. We had to replace them all again, but the initial failure was not the drives this time. Using Dirvish, we have everything from quarterly backups going back years, to daily backups that go back 2 weeks from today. Several times, we've had users asking if we can recover a file they can't find anymore or just need an older copy they no longer have. We do have a few options beyond the default, -A, -H, and -X, for rsync to ensure all metadata is backed up so it's restored as closely as possible when we have to do bare-metal restores. Just some ideas, Loren > > TIA > > > _______________________________________________ > PLUG mailing list > [email protected] > http://lists.pdxlinux.org/mailman/listinfo/plug _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
