On Fri, Oct 16, 2009 at 1:40 PM, Erik Trimble <erik.trim...@sun.com> wrote:
> Prasad Unnikrishnan wrote: > >> Add the new disk - start writing new blocks to that disk, instead of >> waiting to re-layout all the stipes. And when the disk is not active, do >> slow/safe copy on write to balance all the blocks? >> >> > Conceptually, yes, doing a zpool expansion while the pool is live isn't > hard to map out, conceptually. > > As always, the devil is in the details. In this case, the primary problem > I'm having is maintaining two different block mapping schemes (one for the > old disk layout, and one for the new disk layout) and still being able to > interrupt the expansion process. My primary problem is that I have to keep > both schemes in memory during the migration, and if something should happen > (i.e. reboot, panic, etc) then I lose the current state of the zpool, and > everything goes to hell in a handbasket. > In a way I think the key of this working is the code for device removal, because when you are removing a device, you take from one and put on another, it should be much easier to use this code and move 1/N of existing data to a new device using functions from device removal modifications, i could be wrong but it may not be as far as people fear. Device removal was mentioned in the Next word for ZFS video. James Dickens http://uadmin.blogspot.com jamesd...@gmail.com > > > -- > Erik Trimble > Java System Support > Mailstop: usca22-123 > Phone: x17195 > Santa Clara, CA > Timezone: US/Pacific (GMT-0800) > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
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