[Lustre-discuss] Lustre 1.6.2 + 2.6.18 - Directory index full!
adilger at clusterfs.com
Fri Sep 28 10:29:02 PDT 2007
On Sep 28, 2007 09:47 -0700, Kevin Fox wrote:
> Is there a reason clustered metadata must be ZFS only?
Because it requires changes to the on-disk directory format of ext3 in
a way that isn't likely to ever make it into upstream ext4 and we don't
want to support that indefinitely (adds a pointer to a remote MDS for an
inode and stores 128-bit file identifiers). Also, we need mechanism to
do name->value lookups in the filesystem (also doesn't exist in ext3).
Both of these are possible with ZFS.
> On Thu, 2007-09-27 at 14:09 -0600, Andreas Dilger wrote:
> > On Sep 27, 2007 16:10 +0200, Niklas Edmundsson wrote:
> > > On Thu, 27 Sep 2007, Andreas Dilger wrote:
> > > >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 suspected something like that. The error message needs some help
> > > though, I'd prefer having the directory in question in there if
> > > possible, or at least some hint on where to look.
> > >
> > > >>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.
> > >
> > > Any idea on the timeframe?
> > The 1.8 release (planned Q1 2008) will allow new filesystems to be created
> > with ZFS OSTs and MDTs. We will require ZFS for clustered MDTs in 2.0
> > (and possibly all backing stores, though it should of course be possible
> > to still use 1.8 OSTs if required).
Principal Software Engineer
Cluster File Systems, Inc.
More information about the lustre-discuss