> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Erik Trimble > > > In the case of resilvering on a mirrored disk, why not take a snapshot, and > then > > resilver by doing a pure block copy from the snapshot? It would be > sequential, > > So, a > ZFS snapshot would be just as fragmented as the ZFS filesystem was at > the time.
I think Mark was suggesting something like "dd" copy device 1 onto device 2, in order to guarantee a first-pass sequential resilver. And my response would be: Creative thinking and suggestions are always a good thing. In fact, the above suggestion is already faster than the present-day solution for what I'm calling "typical" usage, but there are an awful lot of use cases where the "dd" solution would be worse... Such as a pool which is largely sequential already, or largely empty, or made of high IOPS devices such as SSD. However, there is a desire to avoid resilvering unused blocks, so I hope a better solution is possible... The fundamental requirement for a better optimized solution would be a way to resilver according to disk ordering... And it's just a question for somebody that actually knows the answer ... How terrible is the idea of figuring out the on-disk order? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
