Hi, >> I am considering building a modest sized storage system with zfs. Some >> of the data on this is quite valuable, some small subset to be backed >> up "forever", and I am evaluating back-up options with that in mind. > > You don't need to store the "zfs send" data stream on your backup media. > This would be annoying for the reasons mentioned - some risk of being able > to restore in future (although that's a pretty small risk) and inability to > restore with any granularity, i.e. you have to restore the whole FS if you > restore anything at all. > > A better approach would be "zfs send" and pipe directly to "zfs receive" on > the external media. This way, in the future, anything which can read ZFS > can read the backup media, and you have granularity to restore either the > whole FS, or individual things inside there. > > Plus, the only way to guarantee the integrity of a "zfs send" data stream is > to perform a "zfs receive" on that data stream. So by performing a > successful receive, you've guaranteed the datastream is not corrupt. Yet.
Thanks for your feedback! My plan is to have near-line back-up on zfs on another physically independent media, much as you describe. Then another copy off-site on separate system (disk), and third copy on WORM-like media in "chunks" somewhere else. I am really looking to have the latter two sliced to fit non-disk media (tape, optical disks, ...), or external storage not really usable as a filesystem (S3, web hosting, ...). The off-site disk is not in zfs-capable system, unless I set up a virtual machine; but it won't have enough physical disks for raidz2 anyway. I am primarily looking for something I can store encrypted in dvd- or tape-sized slices on at least two physically separate media. This backup would be used when at least two other media have already been lost, so while convenience is a plus I really desire reliability and longevity. (Yes I know tapes and DVDs die too.) I appreciate the comments by others on zfs send not allowing individual file restore, but as I wrote before this is not very important to me, at least not as important than my other questions. Apropos, is anyone able to respond to those? (Is format documented, independent tools, bugs known to have affected send/restore, would you recommend over tar/pax in real life, etc.) I am very interested in what people have actually done and experienced in real life, including disaster recovery from multiple media failure. Regards, Lassi _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
