[lustre-discuss] Large directory feature is not enabled

[Scott Shaw]

I am running into a problem with a MDTEST benchmark with a single directory.  It appears I hit a file limit per directory using a single directory but a unique directory test completes successfully.  While running the metadata benchmark I ran into the following error message.   

MDS Server log file:
Apr 24 08:45:38 lst-ddn kernel: LDISKFS-fs warning (device md0): ldiskfs_dx_add_entry: Large directory feature isnot enabled on this filesystem
Apr 24 08:45:39 lst-ddn kernel: LDISKFS-fs warning (device md0): ldiskfs_dx_add_entry: Directory (ino: 1149763587) index full, reach max htree level :2
Apr 24 08:45:39 lst-ddn kernel: LDISKFS-fs warning (device md0): ldiskfs_dx_add_entry: Large directory feature isnot enabled on this filesystem

How do I enable the "Large directory feature"?  Checking HPDD Intel site, this feature htree level 3 is still in the works.  We are using Lustre v2.6 but the website is not clear to me if there is a temporary workaround to solve this issue.

Following is the MDTEST command line executed on the compute nodes and the output;

Command line used: ../mdtest-1.9.3/mdtest -d /lustre/sshaw/mdtest -z 0 -b 0 -n 65536 -C -T -r -F
Path: /lustre/sshaw
FS: 1198.9 TiB   Used FS: 2.1%   Inodes: 1185.5 Mi   Used Inodes: 0.3%

384 tasks, 25165824 files
04/24/2015 08:46:07: Process 14(r1i0n0): FAILED in create_remove_items_helper, unable to create file: No space left on device
04/24/2015 08:46:08: Process 23(r1i0n0): FAILED in create_remove_items_helper, unable to create file: No space left on device

Any ideas how to resolve this issue by enabling "large directory feature"?  

Scott