High load and file access performance issues using cluster suite and GFS

Installing, Configuring, Troubleshooting server daemons such as Web and Mail
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Joined: 2007/02/07 16:38:06

High load and file access performance issues using cluster s

Post by eztarg3t » 2008/08/28 18:22:24

We recently replaced our very old file server that was running OSF and it's cluster software with the following conifguration:

2 x Dell 2950's dual duo-core w/15GB ram connected to a SAN over fiberchannel.

Centos 4.6 with CSGFS packages, all yum updated.

The only thing we are using this for is nfs exports only to multiple nfs clients.

Under what I would consider fairly low usage, the cluster is struggling pretty badly, with load averages at times hovering around 8-10 for hours at a time (our old fileserver by comparison, would rarely get above 1.5-2).

For speed, we do all of your mounting UDP. After launching and having load averages staying around 25, I increased the number of nfs processes from the default to 256, and that made a big difference, but it is still no where
like it should be. With 4-5 clients doing reads, and 1-2 clients doing a lot of small file writes, the load jumps up to the 8-10 I discussed earlier.

I have not had a lot of luck finding people using the CSGFS stuff on centos and therefore no tuning tweaks beyond what is the the public documentation for it.

If anyone has any experience/ideas on helping to resolve this, it would be greatly appreciated. All we're doing is serving files, I can't understand why that is so difficult for this software!



Posts: 59
Joined: 2007/02/07 16:38:06

Re: High load and file access performance issues using cluster suite and GFS

Post by eztarg3t » 2008/08/28 19:20:13

I have an update. I can easily create a load spike with very little effort. We have a samba server that mounts this file server via nfs, and serves user shares via cifs. If I map my home directory from a windows client to our samba server, and ran a virus scan on my home directory which was slightly less than 5000 files. It was fast, only took 1 minute 20 seconds, and the samba server saw virtually no effects, but the file server itself jumped to a load of 6.5 during the scan.

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