> If it is true that unlike ZFS itself, the replication > stream format has > no redundancy (even of ECC/CRC sort), how can it be > used for > long-term retention "on tape"?
It can't. I don't think it has been documented anywhere, but I believe that it has been well understood that if you don't trust your storage (tape, disk, floppies, punched cards, whatever), then you shouldn't trust your incremental streams on that storage. It's as if the ZFS design assumed that all incremental streams would be either perfect or retryable. This is a huge problem for tape retention, not so much for disk retention. On a personal level I have handled this with a separate pool of fewer, larger and slower drives which serves solely as backup, taking incremental streams from the main pool every 20 minutes or so. Unfortunately that approach breaks the legacy backup strategy of pretty much every company. I think the message is that unless you can ensure the integrity of the stream, either backups should go to another pool or zfs send/receive should not be a critical part of the backup strategy. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
