diff options
| author | NeilBrown <neilb@suse.de> | 2006-06-26 00:27:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-26 09:58:37 -0700 |
| commit | c93983bf517c100a31e40ef087e19bd3d7aa2d28 (patch) | |
| tree | 9361c68d5f00ccd34cbc0a3bc7bc2389ce7f4c3a /include/linux/raid | |
| parent | 7c7546ccf6463edbeee8d9aac6de7be1cd80d08a (diff) | |
[PATCH] md: support stripe/offset mode in raid10
The "industry standard" DDF format allows for a stripe/offset layout where
data is duplicated on different stripes. e.g.
A B C D
D A B C
E F G H
H E F G
(columns are drives, rows are stripes, LETTERS are chunks of data).
This is similar to raid10's 'far' mode, but not quite the same. So enhance
'far' mode with a 'far/offset' option which follows the layout of DDFs
stripe/offset.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/raid')
| -rw-r--r-- | include/linux/raid/raid10.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/raid/raid10.h b/include/linux/raid/raid10.h index b1103298a8c..c41e56a7c09 100644 --- a/include/linux/raid/raid10.h +++ b/include/linux/raid/raid10.h @@ -24,11 +24,16 @@ struct r10_private_data_s { int far_copies; /* number of copies layed out * at large strides across drives */ + int far_offset; /* far_copies are offset by 1 stripe + * instead of many + */ int copies; /* near_copies * far_copies. * must be <= raid_disks */ sector_t stride; /* distance between far copies. - * This is size / far_copies + * This is size / far_copies unless + * far_offset, in which case it is + * 1 stripe. */ int chunk_shift; /* shift from chunks to sectors */ |