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| author | Guoqing Jiang <gqjiang@suse.com> | 2017-03-01 11:42:40 +0300 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-03-17 02:55:50 +0300 |
| commit | 818da59f97d6764edb91fa9d1f63d333d54eb999 (patch) | |
| tree | c63c89cc1e0293d75685f3639c41a381acf7be13 /Documentation/md/md-cluster.txt | |
| parent | b98938d16a108d0201d54b8db1337dac71aebfdd (diff) | |
| download | linux-818da59f97d6764edb91fa9d1f63d333d54eb999.tar.xz | |
md-cluster: add the support for resize
To update size for cluster raid, we need to make
sure all nodes can perform the change successfully.
However, it is possible that some of them can't do
it due to failure (bitmap_resize could fail). So
we need to consider the issue before we set the
capacity unconditionally, and we use below steps
to perform sanity check.
1. A change the size, then broadcast METADATA_UPDATED
msg.
2. B and C receive METADATA_UPDATED change the size
excepts call set_capacity, sync_size is not update
if the change failed. Also call bitmap_update_sb
to sync sb to disk.
3. A checks other node's sync_size, if sync_size has
been updated in all nodes, then send CHANGE_CAPACITY
msg otherwise send msg to revert previous change.
4. B and C call set_capacity if receive CHANGE_CAPACITY
msg, otherwise pers->resize will be called to restore
the old value.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'Documentation/md/md-cluster.txt')
| -rw-r--r-- | Documentation/md/md-cluster.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/md/md-cluster.txt b/Documentation/md/md-cluster.txt index 38883276d31c..2663d49dd8a0 100644 --- a/Documentation/md/md-cluster.txt +++ b/Documentation/md/md-cluster.txt @@ -321,4 +321,4 @@ The algorithm is: There are somethings which are not supported by cluster MD yet. -- update size and change array_sectors. +- change array_sectors. |