[Lustre-devel] Moving ldiskfs external to the Lustre tree
Christopher J. Morrone
morrone2 at llnl.gov
Wed Oct 12 14:44:32 PDT 2011
We would like to see the ldiskfs tree removed from the lustre tree and
made an independent package. I have been floating this idea
unofficially for a while, but I would like to now officially propose
this for Lustre 2.2.
With the OBD changes that are taking place on the Orion branch, we want
to make lustre be able to use any of a number of backend filesystems.
The current tree and configure tools make it very hard to build without
ldiskfs (instead using zfs, btrfs, or something we haven't thought of
yet). As part of cleaning that up, moving ldiskfs external to lustre
will help ensure that we don't have unnecessary dependencies crop up in
We have created an external package of the ldiskfs tree and put it up on
To use the new external ldiskfs package with lustre, you will also need
a few patches to lustre itself. There are links to the patches in this
On a RHEL system, ldiskfs has a build dependency on the kernel-debuginfo
packages by default. That is where we find the ext4 source code.
Building should be fairly straight forward. Build and install ldiskfs
(in particular the lustre-ldiskfs-devel package), and then build lustre.
The main new change to lustre is the addition of the configure option
"--with-ldiskfs-devel". On a RHEL system if you have the
lustre-ldiskfs-devel package installed, you won't need to give a path.
Note that we have not yet removed the in-tree ldiskfs. Our first step
was to get this working. Once this is accepted, we will be happy to
submit the patches to remove lustre's copy of ldiskfs and generally
clean up lustre's autoconf checks involving ldiskfs.
We attempted to keep the changes minimal, so we didn't change the name
of the ldiskfs rpm packages. But we think is would be nice to change
the name from "lustre-ldiskfs" to simply "ldiskfs". If we want to make
that change, now is the time to do it.
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