A stable version of the GFS2 cluster filesystem
A cluster filesystem allowing simultaneous access to shared storage from multiple nodes, designed for SAN environments. It is also possible to use GFS2 as a single node (local) filesystem by selecting the lock_nolock lock "module".
- Name: Steven Whitehouse
- email: <firstname.lastname@example.org>
- mailing list: <email@example.com>
- Targeted release: Fedora 21
- Last updated: (04/02/2009)
- Percentage of completion: 90%
GFS2 is part of the upstream kernel, but is still listed as experimental. The plan is that this will become stable before the release of F-11. Also the gfs2-utils package is part of Fedora already, and again we hope to declare this stable before F-11.
Benefit to Fedora
The main benefit is a stable cluster filesystem which works seamlessly with the Red Hat cluster infrastructure.
Most of the remaining work now is testing and bug fixing.
How To Test
Read the docs, create a filesystem, run an application on it, check to see whether there are any problems/bugs and if so report them via the usual bugzilla process.
We will also be running the Red Hat QE tests, some performance tests and basically anything else that we can get our hands on in order to try and cover as many possible tests as possible. Any filesystem test suite would be a good thing to test with, whether for performance or correctness. We also want to see lots of testing with real applications, Apache, Samba, NFS (over GFS2), exim, sendmail, yourfavouriteapplicationhere, etc. Basically anything that uses the filesystem.
You don't need any special hardware to do single node tests - you can create a filesystem in a single file and mount it loopback. For multiple node tests you will need some shared storage (iSCSI, FC, or some other kind of SAN) plus a method of fencing failed nodes (this can be done manually if you don't have any fencing hardware, but power switches and/or remote access controllers are recommended).
If everything is working correctly, the results should be exactly the same as you'd expect running the application on a local filesystem. One point to watch though is that many applications are not written to run in a clustered environment, so if you are expecting multiple copies of an application to share the same set of data files, then please check that the application does support this mode of operation first. Usually it will require some method for inter-node communication at the application level.
The GFS2 filesystem allows sharing of a filesystem across multiple nodes in an HA environment.
This feature depends on the cman package, the corosync package and the dlm kernel module, which are already part of Fedora.
If this is not ready in time, we can just push out that date at which we consider GFS2 stable. There are no other packages at the moment which depend on this feature.
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