@@ -179,8 +179,9 @@ OPTIONS
Resets any previous effects of *--verbose*.
-U|--uuid <UUID>
- Create the filesystem with the given *UUID*. The UUID must not exist on any
- filesystem currently present.
+ Create the filesystem with the given *UUID*. For a single-device filesystem,
+ you can duplicate the UUID; however, for a multi-device filesystem, the UUID
+ must not already exist on any currently present filesystem.
-v|--verbose
Increase verbosity level, default is 1.
@@ -430,7 +430,7 @@ static const char * const mkfs_usage[] = {
OPTLINE("-s|--sectorsize SIZE", "data block size (may not be mountable by current kernel)"),
OPTLINE("-O|--features LIST", "comma separated list of filesystem features (use '-O list-all' to list features)"),
OPTLINE("-L|--label LABEL", "set the filesystem label"),
- OPTLINE("-U|--uuid UUID", "specify the filesystem UUID (must be unique)"),
+ OPTLINE("-U|--uuid UUID", "Specify the filesystem UUID (must be unique for a filesystem with multiple devices)"),
"Creation:",
OPTLINE("-b|--byte-count SIZE", "set size of each device to SIZE (filesystem size is sum of all device sizes)"),
OPTLINE("-r|--rootdir DIR", "copy files from DIR to the image root directory"),
The commit ("btrfs-progs: allow duplicate fsid for single device filesystems") lets the duplicate fsid used for a new mkfs document this. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- David, This patch can be folded into patch: ff4c4a3a00db btrfs-progs: allow duplicate fsid for single device filesystems in your devel. Documentation/mkfs.btrfs.rst | 5 +++-- mkfs/main.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-)