Maybe to create snapshots "after the fact" as a part of some larger disaster recovery effort. (What did my pool/file-system look like at 10am?... Say 30-minutes before the database barffed on itself...)
With some enhancements might this functionality be extendable into a "poor man's CDP" offering that won't protect against (non-redundant) hardware failures, but can provide some relieve in App/Human creativity. Seems like one of those things you never really need... Until you have to that one time, at which point nothing else will do. One would think that using zdb and friends it might be possible to "walk the chain" of tx-logs backwards and each good/whole one could be a valid recover/reset-point. -- This raises a more fundamental question that perhaps someone can comment on. Does ZFS's COW follow a fairly strict last released-block, last overwritten model (keeping a maximum buffer of "in tact" data), or do previously used blocks get overwritten largely based on block/physical location, fragmentation/best-fit, etc?). In cases of blank disks/LUNs, does for instance a 1TB drive get completely COW-ed onto its blank-space, or does zfs re-use previously used (and freed) space before burning through then entire disk-space? Thanks, -- MikeE -----Original Message----- From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-boun...@opensolaris.org] On Behalf Of Orvar Korvar Sent: Monday, November 09, 2009 8:36 AM To: zfs-discuss@opensolaris.org Subject: [zfs-discuss] PSARC recover files? This new PSARC putback that allows to rollback to an earlier valid uber block is good. This immediately raises a question: could we use this PSARC functionality to recover deleted files? Or some variation? I dont need that functionality now, but I am just curious... -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
