Clustered Samba for GFS2
Support for active-active samba sharing over GFS2 using CTDB.
- Name: Abhijith Das
- email: firstname.lastname@example.org
- Targeted release: Fedora 12
- Last updated: 7/20/2009
- Percentage of completion: 70%
With the availability of a clustered database (CTDB) for Samba, multiple instances of smbd across different nodes of a cluster are able to share state. It is now possible to share the same directory in a clustered GFS2 filesystem via Samba+CTDB from all the nodes of a cluster to facilitate Active/Active Samba sharing.
Benefit to Fedora
Active/Active sharing of Samba services was not possible over GFS2 (or any other clustered filesystem) on Fedora before this feature was implemented. With this it's possible now.
- fcntl posix locks performance: Improve upon gfs2's posix lock performance (single-node & clustered) as smbd uses them extensively when posix locking is turned on.
- Get CTDB and CTDB-supported Samba packages into F-12.
- Get Conga interface ready for manipulating the various config files (/etc/cluster/cluster.conf, /etc/sysconfig/ctdb, /etc/samba/smb.conf) through web-based GUI. (Alternative to hand-editing configs)
- Verify working of clustered-samba use cases and document respective configuration parameters.
This feature will not affect the operation of non-clustered samba setups or other gfs2-based setups. This feature will provide the capability to do clustered-samba-over-gfs2 that was not available before.
How To Test
1. smbtorture tests like RAW_BENCH_LOCK (posix locking = on), RAW_BENCH_OPEN, BENCH_NBENCH and the ctdb ping_pong test are to be run on a samba+ctdb+gfs2 cluster.
- Basic Configuration:
- Setup a cluster with your machines: <link>
- mount a gfs2-formatted clustered volume at the same mountpoint on all nodes.
- export this mountpoint (or a directory within it) as a samba share. All smb.conf files in all nodes should be identical
- Set ctdb configuration <link>
- start the ctdb service and check 'ctdb status' to make sure the ctdb cluster is up.
- Now you should simultaneously be able to access the samba share through all the exporting nodes and run operations on them simultaneously.
Users not using gfs2, samba or ctdb should notice no change. Users will now have the ability to run a clustered samba setup exporting gfs2 shares.
Most of the kernel support (gfs2 filesystem) is already upstream. ctdb and samba packages have been included in Fedora.
In it's current state, a basic clustered samba setup should work. Enhancements such as posix lock performance & conga interface and testing of different use-cases would be nice to get done with. If not done with these tasks, in it's current form, the feature is still acceptable.
-  about ctdb
-  about samba
- Cluster Suite on Wikipedia
- GFS/GFS2 on Wikipedia
- Cluster Wiki page
- GFS2 kernel documentation (a very basic introduction)