Emil Mikulic wrote: > On Wed, Sep 02, 2009 at 09:20:21AM +0200, Mark Stapper wrote: > >> updating a zfs filesystem which you are running from is next to >> impossible. >> > > [citation needed] :) > Well, to update your zfs filesystem version, the filesystem is first unmounted, then updated, and then mounted again. citation coming up! # umount / umount: unmount of / failed: Invalid argument > >> So, i would recommend setting up gmirror to mirror your whole disks, >> install the base system(boot and "world") on a small UFS slice, and use >> the rest of the disc as zfs slice. >> > > As Thomas Backman pointed out, this means you won't get self-healing. > self-healing sounds very nice, but with mirrorring you have data on two discs, so in that case there no "healing" involved, it's just checksumming and reading the non-corrupted copy. From the gmirror manpage: "All operations like failure detection, stale component detection, rebuild of stale components, etc. are also done automatically." This would indicate the same functionality, with a much less fancy name. However, i have not tested it the way they demonstrate zfs's "self-healing" property. I might, if I get the time to run it in a virtual machine one of these days.. > I don't know if a ZFS mirror performs smarter disk access scheduling > than gmirror. Someone oughta measure. ;) > NCQ should help here, but still, very interesting. gmirror is fast though. I've even heard it's faster than software RAID1/ataraid. (not confirmed). Even if this is true, running zfs on top of gmirror probably isn't faster then running zfs with a mirrored pool.
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