# mkdir d0
# lfs getstripe -m d0
0
# lfs getdirstripe d0
lmv_stripe_count: 0 lmv_stripe_offset: 0 lmv_hash_type: none
# lfs migrate -c2 d0
error: lfs migrate: d0: cannot open source file: Is a directory
# lfs migrate -m0 -c2 d0
# lfs getstripe -m d0
0
# lfs getdirstripe d0
lmv_stripe_count: 2 lmv_stripe_offset: 0 lmv_hash_type: fnv_1a_64
mdtidx		 FID[seq:oid:ver]
     0		 [0x200000400:0x2:0x0]		
     1		 [0x240000401:0x2:0x0]		

 lfs help migrate
migrate: migrate a directory between MDTs.
usage: migrate [--mdt-count|-c] <stripe_count>
		 [--mdt-hash|-H] <hash_type>
               [--mdt-index|-m] <start_mdt_index>
		 [--verbose|-v]
		 <directory>
	mdt:	MDTs to stripe over, if only one MDT is specified
			it's the MDT index of first stripe
	mdt_count:	number of MDTs to stripe a directory over
	mdt_hash:	hash type of the striped directory. mdt types:
		all_char  (type 1)sum of characters % MDT_COUNT
		fnv_1a_64 (type 2)FNV-1a hash algorithm (default)

migrate file objects from one OST layout
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