k:lustre# rm f0 f0.mirror~2
k:lustre# dd if=/dev/urandom of=f0 bs=1M count=1
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.0147195 s, 71.2 MB/s
k:lustre# md5sum f0
f48d2d25f34b5afe5ea60b48da362b8d f0
k:lustre# lfs mirror extend -N -p ddn_ssd f0
k:lustre# echo XXX > f0
k:lustre# lfs mirror read --mirror-id=1 f0 | wc
1 1 4
k:lustre# lfs mirror read --mirror-id=2 f0 | wc
0 1 4
k:lustre# lfs mirror split --mirror-id=2 f0
k:lustre# stat f0 f0.mirror~2
File: ‘f0’
Size: 4 Blocks: 8 IO Block: 4194304 regular file
Device: 2c54f966h/743766374d Inode: 144115205289279535 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2020-12-01 12:45:59.000000000 -0600
Modify: 2020-12-01 12:46:23.000000000 -0600
Change: 2020-12-01 12:46:23.000000000 -0600
Birth: -
File: ‘f0.mirror~2’
Size: 1048576 Blocks: 2048 IO Block: 4194304 regular file
Device: 2c54f966h/743766374d Inode: 144115205289279538 Links: 1
Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2020-12-01 12:46:57.000000000 -0600
Modify: 2020-12-01 12:46:57.000000000 -0600
Change: 2020-12-01 12:46:57.000000000 -0600
Birth: -
k:lustre# md5sum f0.mirror~2
f48d2d25f34b5afe5ea60b48da362b8d f0.mirror~2