I guess not all usage scenarios are comparable, but I once tried to use GFS2 as well as OCFS2 to share a FC SAN to three nodes using 8GBit FC and 1GBit Ethernet for the cluster communication. Additionally, i compared it to a trial version of Dataplows SAN File System (SFS). I was also supposed to compare it to Quantum StorNext, but there just wasn't enough time for that. OS was CentOS 5.3 at that time. So I tried a lot of performance tuning settings for all three, and it was like this: 1.) SFS was the fastest, but caused reproducible kernel panics. Those were fixed by Dataplow, but then SFS produced corrupted data when writing large files. Unusable in that state, so we gave up. SFS uses NFS for lock management. Noteworthy: Writing data on the machine with the NFS lock manager also crippled the I/O performance for all the other nodes in a VERY, VERY bad way.. 2.) GFS2 was the slowest, and despite all the tunings I tried, it never came close to anything that any local FS would provide in terms of speed (compared to EXT3 and XFS). The statfs() calls pretty much crippled the FS. Multiple I/O streams on multiple nodes: Not a good idea it seems.. Sometimes you have to wait for minutes for the FS to just give you any feedback, when you're hammering it with let's say 30 sequential write streams across 3 nodes, with the streams equally distributed among them. 3.) OCFS2 was slightly faster than GFS2, especially when it came to statfs(), like ls -l. It did not slow down that much. But overall, it was still just far too slow. Our solution: Hook up the SAN on one node only, and share via NFS over GBit Ethernet. Overall, we are getting better results even with the obvious network overhead, especially when doing a lot of I/O on multiple clients. Our original goal was to provide a high-speed centralized storage solution for multiple nodes without having to use ethernet. This failed completely unfortunately. Hope this helps, it's just my experience though. As usual, mileage may vary... yue wrote:
which is better gfs2 and ocfs2? i want to share fc-san, do you know which is better? stablility,performmance?
-- Michael Lackner Lehrstuhl fÃr Informationstechnologie, MontanuniversitÃt Leoben IT Administration michael.lackner@xxxxxxxxxxxx | +43 (0)3842/402-1505 -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
