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| author | NeilBrown <neilb@suse.de> | 2020-10-14 13:12:48 +1100 |
|---|---|---|
| committer | Jes Sorensen <jsorensen@fb.com> | 2020-10-14 11:40:40 -0400 |
| commit | 97b51a2c2d00b79a59f2a8e37134031b0c9e0223 (patch) | |
| tree | 1958109eec5a7e8926e2ecfaac02a90ecd00187b /md.4 | |
| parent | 7f3b2d1d1621cbdc60b5af4a41445391010fe9e1 (diff) | |
| download | mdadm-97b51a2c2d00b79a59f2a8e37134031b0c9e0223.tar.gz | |
Super1: allow RAID0 layout setting to be removed.
Once the RAID0 layout has been set, the RAID0 array cannot be assembled
on an older kernel which doesn't understand layouts.
This is an intentional safety feature, but sometimes people need the
ability to roll-back to a previously working configuration.
So add "--update=layout-unspecified" to remove RAID0 layout information
from the superblock.
Running "--assemble --update=layout-unspecified" will cause the assembly
the fail when run on a newer kernel, but will allow it to work on
an older kernel.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>
Diffstat (limited to 'md.4')
| -rw-r--r-- | md.4 | 13 |
1 files changed, 13 insertions, 0 deletions
@@ -215,6 +215,19 @@ option or the .B "--update=layout-alternate" option. +Once you have updated the layout you will not be able to mount the array +on an older kernel. If you need to revert to an older kernel, the +layout information can be erased with the +.B "--update=layout-unspecificed" +option. If you use this option to +.B --assemble +while running a newer kernel, the array will NOT assemble, but the +metadata will be update so that it can be assembled on an older kernel. + +No that setting the layout to "unspecified" removes protections against +this bug, and you must be sure that the kernel you use matches the +layout of the array. + .SS RAID1 A RAID1 array is also known as a mirrored set (though mirrors tend to |