[LU-3955] Eliminate ldiskfs recursive & independent rpm packaging

• Type: Technical task
• Resolution: Fixed
• Priority: Major
• Affects Version/s: Lustre 2.5.0
• Assignee: Minh Diep
• Reporter: Christopher Morrone (Inactive)

Description

ldiskfs is a prerequisite of lustre. But instead of building the prerequisite before lustre, we have chosen to stop and perform the build of in the middle of the lustre. That introduces a great deal of unnecessary complexity to the lustre build system. The complexity is so great, that we have allowed the normal* way of building RPMs to remain broken for years. Our .src.rpm files remain unbuildable under many normal situations.

To make further progress on LU-1199, this major problem must be addressed. As I see it, there are two main solutions we could choose:

1. Move ldiskfs out of the lustre source tree. Build it first.
2. Keep ldiskfs in-tree, but eliminate its independant build system and spec file. The ldiskfs binary rpm becomes a sub-module of lustre.spec.

I have been moving us towards option 1. I have gotten enough change landed to allow ldiskfs to be built out of tree. It will not take much change to allow Lustre to use the externally pre-build ldiskfs packages. We already do this at LLNL, so I'm pretty clear on what needs to be done there.

I think option 1 would also position us nicely is James Simmons is successful in getting all of the ldiskfs into the upstream kernel at some point. We will already be comfortable at that point building against an ldiskfs that is out of tree.

It is also nicely symmetric with how we build against an external zfs today (and perhaps btrfs in the future). Even if we wind up needed to make an "lbtrfs" in the future, I don't think we would want to repeat the choice to try to merge that into the lustre tree.

I would like to see a quick decision from Intel on which path we should take for Lustre 2.5, so that we can get the change introduced early in the development cycle. That will give us some time to adjust all of our personal processes, and get the kinks worked out well in advance of release.

* I am defining "normal" to be the way that a distro like fedore would do it: first build ldiskfs rpms, including devel packages. Then build lustre against the already built ldiskfs packages.

Issue Links

• duplicates: LU-3462 Eliminate ldiskfs recursive & independent rpm packaging