Quoth Darren J Moffat on Thu, Dec 21, 2006 at 03:31:59PM +0000: > Pawel Jakub Dawidek wrote: > >I like the idea, I really do, but it will be soooo expensive because of > >ZFS' COW model. Not only file removal or truncation will call bleaching, > >but every single file system modification... Heh, well, if privacy of > >your data is important enough, you probably don't care too much about > >performance. > > I'm not sure it will be that slow, the bleaching will be done in a > separate (new) transaction group in most (probably all) cases anyway so > it shouldn't really impact your write performance unless you are very > I/O bound and already running near the limit. However this is > speculation until someone tries to implement this!
Bleaching previously used blocks will corrupt files pointed to by older uberblocks. I think that means that you'd have to verify that the new uberblock is readable before you proceed, since part of ZFS's fault tolerance is falling back to the most recent good uberblock if the latest one is corrupt. I don't think this makes bleaching unworkable, but the interplay will require analysis. David _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
