On Wed, 2005-09-28 at 15:47 -0400, Bill Davidsen wrote: > Dan Stromberg wrote: > > >On Sat, 2005-08-27 at 15:00 +1000, Daniel Pittman wrote: > > > > > >>"Guy" <bugzilla@xxxxxxxxxxxxxxxx> writes: > >> > >>[...] > >> > >> > >> > >>>>I've been working on a RAID setup with dual RAID controllers and > >>>>three expansion boxes - 48 disks in all, including data, parity and > >>>>global spares. > >>>> > >>>> > >>[...] > >> > >> > >> > >>>>They don't feel that the storage has to be blazing fast, and 100% uptime > >>>>isn't paramount, however they very much do not want to lose their data. > >>>> > >>>>The filesystem will not be backed up - we simply don't have anything large > >>>>enough to back it up -to-, so if the some part of the storage solution > >>>>goes kerflooey, we're totally... er... out of luck, and they'll probably > >>>>be looking at me (the primary sysadmin on the storage configuration), > >>>>wondering why their data is gone. > >>>> > >>>> > >>>RAID5, 6 or 1 is not data backup! It is hardware redundancy!! > >>>Data loss or corruption can still occur with a RAID solution. RAID won't > >>>help if someone fat fingers a "rm" command. > >>>Corruption of the filesystem can also cause major data loss, without a > >>>failed disk. > >>> > >>>If the data was lost, what would it cost to re-create it? > >>>Enough to buy a backup system? > >>> > >>> > >>I absolutely agree with this. When - and it is when, not if - the > >>content of this filesystem goes away, you will be rightly blamed for it. > >> > >>Invest the few thousand dollars in a good high capacity tape drive and > >>pay someone to change the tapes. This will be worth it when the system > >>finally does fail in some nasty, unpredictable way! > >> > >> > > > >I was on paternity leave when the solution was selected, but the guy > >with the grant money has been disinterested in backups from the > >beginning. > > > >The policy is going to be "your homedir will be backed up. Your files > >under /data will not, unless you back them up yourself." > > > >My job is to work within that restriction, and possibly advise for > >backups, but nothing more. The purchasing decision is not mine. > > > Clearly you have some input into it. I would suggest that you at least > go on record (paper trail CYA) on the need for backup. If you can't get > incrementals on whatever does the /home directories, at least you could > suggest a DVD burner and regular backups. That is a tiny bump on the > hardware budget, and small storage requirement. You could backup as many > datasets as will fit on one DVD every day, oldest unsaved first. Then > when it fails you will be the hero ;-) We actually have decent backups of /home. It's /data that won't be backed up, unless the users make their own arrangements. I kind of like the idea of doing incrementals to DVD or something, augmented by md5 or sha-* signatures, but I don't think it's going to happen. I've already discussed this with my management, and with the PI. Thanks though. Your advice is helpful. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
