[Lustre-discuss] Lustre 1.6.2 + 2.6.18 - Directory index full!

[Andreas Dilger]

On Sep 27, 2007  10:53 +0200, Niklas Edmundsson wrote:
> We have 13701222 files in one directory, and creating more files there 
> fails even though we have lots of free inodes in the filesystem.

We generally only test up to 10M files in a single directory.  If you had
a perfect hash distribution you might be able to get to 25M files in the
directory.

I suspect if you run "e2fsck -fD" it might help you (its job is to pack
the directories), but I suspect it has never been run on such a large
directory and might conceivably use too much RAM to run on the system.

> On MDS we get this in the kernel log:
> [692361.061558] LDISKFS-fs warning (device sdb2): ldiskfs_dx_add_entry: Directory index full!

This is one of the reasons we are moving to ZFS for the back-end storage.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.