diff options
| author | David Teigland <teigland@redhat.com> | 2019-10-08 09:59:38 -0500 |
|---|---|---|
| committer | David Teigland <teigland@redhat.com> | 2019-10-08 09:59:38 -0500 |
| commit | 53b97b146df4de99207c580c1304d016832e318b (patch) | |
| tree | 200a9abdd4cc8f064a8e3fb1c17358174248bc4d | |
| parent | b6240c91882a98df9eceab0312eec893b7051765 (diff) | |
| download | lvm2-53b97b146df4de99207c580c1304d016832e318b.tar.gz | |
man: lvmcache note dm-cache block size issue
| -rw-r--r-- | man/lvmcache.7_main | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/man/lvmcache.7_main b/man/lvmcache.7_main index 9f3e526af..0eefc8950 100644 --- a/man/lvmcache.7_main +++ b/man/lvmcache.7_main @@ -140,6 +140,21 @@ metadata.) This can be used with dm-cache. \& +.SS dm-cache block size + +\& + +A cache pool will have a logical block size of 4096 bytes if it is created +on a device with a logical block size of 4096 bytes. + +If a main LV has logical block size 512 (with an existing xfs file system +using that size), then it cannot use a cache pool with a 4096 logical +block size. If the cache pool is attached, the main LV will likely fail +to mount. + +To avoid this problem, use a mkfs option to specify a 4096 block size for +the file system, or attach the cache pool before running mkfs. + .SS dm-writecache block size \& |