Date: Thu, 8 Nov 2012 21:39:09 +0200 From: Nikolay Denev <ndenev@gmail.com> To: Daniel Kalchev <daniel@digsys.bg> Cc: freebsd-fs@freebsd.org Subject: Re: zfs remove vdev functionality Message-ID: <393C72B3-7231-47C6-ABD2-1C6BA166ED11@gmail.com> In-Reply-To: <509BF0A2.2050600@digsys.bg> References: <509BF0A2.2050600@digsys.bg>
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On Nov 8, 2012, at 7:49 PM, Daniel Kalchev <daniel@digsys.bg> wrote: > I was thinking on how to implement vdev removal on ZFS and came to = this idea: >=20 > If we can have an per-vdev flag that prohibits new allocations on the = vdev, but permits reads and frees - then we could mark so the vdev we = intend to remove form the zpool and issue an scrub-like command that = will rewrite all blocks allocated form that particular vdev. Since ZFS = is COW, this will effectively move all blocks off that "no write" vdev = and we can now detach it. >=20 > All this could be implemented with the new ZFS feature flags, so no = version bumps etc are necessary. >=20 > Is there something I didn't think of? >=20 > Daniel > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" I don't think this will be that easy, because of snapshots, clones etc. There was a project that you are probably aware of called BP Rewrite = (block pointer rewrite), that was interrupted by Sun-Oracle merger. It very well may be still = being worked on in Sun, who knows :) The closest thing to your idea that I seem to find is this : = https://www.illumos.org/issues/1051 Cheers, Nikolay=
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