On Mon, Jun 6, 2016 at 7:19 PM, Kai Hendry <hendry@xxxxxx> wrote: > On Mon, 6 Jun 2016, at 10:16 PM, Austin S. Hemmelgarn wrote: >> Based on the fact that you appear to want to carry a disk to copy data >> more quickly than over then internet, then what you've already done plus >> this is the correct way to do it. > > The trouble is the way I ended up doing it: > 1) Replacing it with a bigger disk > 2) Deleting the disk > 3) btrfs send /mnt/raid1/snapshot | btrfs receive /mnt/onetb/ > > This took almost **an entire day** over USB3 spinning disks ! > > My expectation was that I could quickly remove a mirrored disk, replace > that disk and hand carry the disk I removed. btrfs shouldn't remove data > from the disk I removed. Had this been a two drive raid1, all you need to do is take one drive with you. No commands necessary. Each drive can be separately mounted with -o degraded, and you can re-establish two copy replication with 'btrfs dev add' with a new drive and 'btrfs dev del missing' to get rid of the phantom missing drive. You'd do that locally and then also at your destination. A gotcha with this technique though is often single chunks get created during the -o degraded read-write mount. After 'dev del missing' completes the replication process, you need to check 'fi df' or 'fi us' for single chunks. If they exist, get rid of them with a filtered balance. '-dconvert=raid1,soft -mconvert=raid1,soft' should work I think. If there are single chunks created and not converted, later if you need to do a degraded mount it will fail. Usually it can be made to work with -o ro,degraded in such a case, but it means no more read-write for the file system, you'd have to recreate it (at this point until it's fixed). -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
