As Andreas says, it isn’t really recommended, but you can get sub-directories
to inherit the striping by using the -D, --default option to `lfs mkdir` or
`lfs setdirstripe`. From the man page:
-D, --default
Set the default striping pattern of subdirectories. Newly cre-
ated sub-directories will use the new default striping pattern,
but existing sub-directories will not be affected. The newly
created sub-directories will also inherit the specified default
striping pattern. Only default stripe count is supported for
now.
Note that striping all directories across all MDTs by default is
not recommended at this time, as the clients will have to do
more RPCs to create and access each directory, hurting perfor-
mance rather than improving it. Default striped directories are
preferred for cases where large subdirectories will be created
(e.g. file-per-process job output directories).
-Cory
On 3/20/20, 2:33 PM, "lustre-discuss on behalf of Andreas Dilger"
<[email protected]<mailto:[email protected]>
on behalf of [email protected]<mailto:[email protected]>> wrote:
On Mar 20, 2020, at 13:02, Mannthey, Keith
<[email protected]<mailto:[email protected]>> wrote:
I am doing some work with Lustre 2.13 (Downloaded from Whamcloud) and DNE 2
there are 6 MDTs.
"
[root@colts52-clx01 for-test]# lfs getdirstripe TEST
lmv_stripe_count: 6 lmv_stripe_offset: 1 lmv_hash_type: fnv_1a_64
mdtidx FID[seq:oid:ver]
1 [0x2c0000400:0x5:0x0]
5 [0x300000403:0x5:0x0]
3 [0x340000403:0x5:0x0]
0 [0x200000403:0x5:0x0]
4 [0x240000402:0x5:0x0]
2 [0x280000401:0x5:0x0]
[root@colts52-clx01 for-test]# mkdir TEST/now
[root@colts52-clx01 for-test]# lfs getdirstripe TEST/now/
lmv_stripe_count: 0 lmv_stripe_offset: 2 lmv_hash_type: none
"
Directory stripping settings are not being propagated. Is this expected?
Yes, this working as designed. It isn't necessarily good for all directories
to be striped, as that adds overhead without necessary improving performance.
The current recommendation is that DNE should be used for e.g. a top-level
directory to distribute files and subdirectories across MDTs, or in the case of
large directories with millions of files.
Cheers, Andreas
--
Andreas Dilger
Principal Lustre Architect
Whamcloud
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