I have been having NFS performance problems with our F820 / 6.2.1R2 for quite some time now. The filer has a GigE card, but when we start pushing about 10MB/sec ( 50 % CPU load ) we get numerous NFS timeouts from solaris clients mounting the filer via tcp. None of the filer stats (statit et all) show any bottleneck on any of the disks. Looking at network traces from a mirrored port, I see the filer at some point reducing tcp window size to 0, down from its normal value - 26280. Looks like it is running out of juice. Any ideas what might be causing this ?
Pawel
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We've experienced the same behaviour. On two separate systems. An F740 running 6.1.2R3 connected to a 420R running Sol 8 using a SUN GigE card. And on an F810 running 6.2.1R2 connected to a V880 running Sol 8 using the onboard GigE port.
We've switched to running NFS v3 over UDP on the F740 (which is the only GigE we have in production on our NetApps). We haven't had any performance issues since. This filer is housing DB/2.
We do have a co-locate F740 connected via GigE to a Linux RedHat machine, but it has only ever been configured to use NFS v2 over UDP with an 8K window size. There is some interest to switch it over to TCP to see if the problems with reducing window size happen there.
On Thu, Jan 23, 2003 at 10:49:49PM -0800, Pawel Rogocz wrote:
I have been having NFS performance problems with our F820 / 6.2.1R2 for quite some time now. The filer has a GigE card, but when we start pushing about 10MB/sec ( 50 % CPU load ) we get numerous NFS timeouts from solaris clients mounting the filer via tcp. None of the filer stats (statit et all) show any bottleneck on any of the disks. Looking at network traces from a mirrored port, I see the filer at some point reducing tcp window size to 0, down from its normal value - 26280. Looks like it is running out of juice. Any ideas what might be causing this ?
Pawel
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Jeff Bryer -
Pawel Rogocz