Hello Yan, On Mon, 29 Dec 2008 11:33:18 pm Yan Zheng wrote:
> 2008/12/29 Chris Samuel <ch...@csamuel.org>: > > > The rebalancing code does appear (from a naive read of the code) to be > > able to rebalance over stripes, but I have no idea if the disk format > > currently supports changing that on the fly. > > The rebalancing moves data/metadata to newly created chunks. If there > are two devices, the new chunks will be set up as RAID-1 by default. Very interesting! I didn't realise that - I was presuming that the BTRFS_BLOCK_GROUP_RAID1 ioctl needed to be passed through (as at mkfs time) to change it into a RAID1 array. Could you point me at the code where this change is detected please ? Just so I can try and wrap my mind around it! > > Again it would appear that you need to have two partitions and that btrfs > > cannot (at present) keep multiple data stripes on the same partition. > > Yes. I think this is due to performance reason. Understood. > Changing the code to support data duplication in single spindle configuration > is easy. OK, that's encouraging (though for my immediate purposes creating two partitions is fine, but it might make life easier for others). Again thanks so much for the response! All the best, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC This email may come with a PGP signature as a file. Do not panic. For more info see: http://en.wikipedia.org/wiki/OpenPGP
signature.asc
Description: This is a digitally signed message part.
