On Thu, February 5, 2009 14:15, Michael McKnight wrote: > I appreciate the discussion on the practicality of archiving ZFS sends, > but right now I don't know of any other options. I'm a home user, so > Enterprise-level solutions aren't available and as far as I know, tar, > cpio, etc. don't capture ACL's and other low-level filesystem attributes. > Plus, they are all susceptible to corruption while in storage, making > recovery no more likely than with a zfs send.
Your big constraint is using optical disks. Certainly there are arguments for single-use media for a backup, but a series of optical disks containing a data stream gives rise to a nasty probability that *one* disk in the set won't be readable, which will render everything after that unrecoverable too. .99 ^ 56 = .57, which is not a probability *I* want to see of fully recovering my data. (.99 is probably pessimistic, though. I hope.) (56 disks is how many my backup would take on DVD-DL disks, and is why I don't do it that way.) External hard drives give you a lot more options. I'm formatting external USB drives as a ZFS pool, and then rsyncing data to them. I can scrub them for verification, and I can easily access individual files. I create snapshots on them so that I can have generations of backup accessible without duplicating data that hasn't changed. I'm currently updating them via rsync, which doesn't propagate ACLs, but I could and should be using send/receive instead, which would. I believe I've figured out the logic, but haven't updated the script. If you do it with send/receive, you get a snapshot on the backup drive that's identical (modulo ZFS bugs) with the original, and which you can scrub to verify when you want, etc. Furthermore, I don't have to be physically present to change and label and file 56 DVD-DL disks. Looks like DL disks are of similar price (per GB) to external USB drives -- and external drives can be used for more than one backup. (Rather similar meaning within a factor of two either way; I only checked prices one place.) -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
