NFS, Can't get request slot

Hi,

We have /usr mounted over NFS on our workstations RH6.2 Server RH 6.2
nfs-utils-0.1.9.1-1
Kernel 2.2.16

These workstations happily use samba and other services without any delays but with NFS they hang in X for up to 15 minutes before NFS come back.
We can ssh into the workstations and use any utility underneath X without any problems whilst it is hung in X.

We have changed the Server eepro100 for a 3com 3c95x with no difference

according to what has been alluded to in other kernel posts.

By the evidence that we have gathered it seems that the Server is not taxed too much as samba users are getting files OK etc. The can't get
request slot is plaguing many others in different ways. It looks like
an NFS issue. How can this be proven? Then we can work on the
problem.

Thanks

--
Grahame Jordan
Network Manager
Interim Technology Training Institute
Mobile: +61 3 0408 058 209
Phone: +61 3 9243 2220
Fax: +61 3 9820 2010
e-mail: [email protected]
Transforming the way people work with technology with INTEGRITY LEARNING INNOVATION TEAMWORK PERFORMANCE

The request queue slot message means the server isnt responding (at least in the eyes of the client). Given you can get into the box that isnt the net card (at least not now). What mount options do you use ?
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Alan,

student:/susr/ /usr nfs
defaults,rsize=1024,wsize=1024 0 0

Thanks

Graham Jordan

--
Grahame Jordan
Network Manager
Interim Technology Training Institute
Mobile: +61 3 0408 058 209
Phone: +61 3 9243 2220
Fax: +61 3 9820 2010
e-mail: [email protected]
Transforming the way people work with technology with INTEGRITY LEARNING INNOVATION TEAMWORK PERFORMANCE

Alan,

On a client running all by itself on our production network overnight, doing an "ls -lR /usr" and doing a compile (in a loop) is giving the same problems.

A little snipit from /var/log/messages

Nov 10 04:31:20 spc81 kernel: nfs: server student OK
Nov 10 04:33:17 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:33:17 spc81 kernel: nfs: server student OK
Nov 10 04:34:59 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:35:04 spc81 kernel: nfs: task 20823 can't get a request slot
Nov 10 04:35:35 spc81 kernel: nfs: server student OK
Nov 10 04:35:35 spc81 kernel: nfs: server student OK
Nov 10 04:44:43 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:44:44 spc81 kernel: nfs: server student OK
Nov 10 04:45:56 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:46:00 spc81 kernel: nfs: task 20457 can't get a request slot
Nov 10 04:46:00 spc81 kernel: nfs: server student OK
Nov 10 04:46:03 spc81 kernel: nfs: server student OK
Nov 10 04:49:15 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:49:15 spc81 kernel: nfs: server student OK
Nov 10 04:49:25 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:52:21 spc81 kernel: nfs: server student OK
Nov 10 04:53:43 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:53:43 spc81 kernel: nfs: server student OK
Nov 10 04:54:01 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:54:02 spc81 kernel: nfs: task 64822 can't get a request slot
Nov 10 04:54:13 spc81 kernel: nfs: server student OK
Nov 10 04:54:15 spc81 kernel: nfs: server student OK
Nov 10 04:55:57 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:55:59 spc81 kernel: nfs: task 29484 can't get a request slot
Nov 10 04:56:21 spc81 kernel: nfs: server student OK
Nov 10 04:56:23 spc81 kernel: nfs: server student OK
Nov 10 04:58:15 spc81 kernel: nfs: server student not responding, still trying
Nov 10 04:58:21 spc81 kernel: nfs: task 1477 can't get a request slot
Nov 10 04:58:52 spc81 kernel: nfs: task 1478 can't get a request slot
Nov 10 04:59:15 spc81 kernel: nfs: server student OK

Shows that under no (or little) load this thing is failing.

We have 20 networks with ~100 machines on each with this same problem. Only a few at a time are using Linux. We are trying to promote Linux as a great operating system, but this is not helping. Again the samba on win95 is puring along nicely plus every other service but for NFS.

We have changed the NIC on this server to 3Com 3c90x for no change in status. Clients are using CNETPro120 200 and Intel eepro100

The servers are generally PIII500 512MB RAM.

We have tried mount flags rsize=1024, 8192, 128, with no change.

It looks like a server issue related to RPC. But I am only guessing here.

Any more help is much appreciated.

Thanks

Grahame Jordan

--
Grahame Jordan
Network Manager
Interim Technology Training Institute
Mobile: +61 3 0408 058 209
Phone: +61 3 9243 2220
Fax: +61 3 9820 2010
e-mail: [email protected]
Transforming the way people work with technology with INTEGRITY LEARNING INNOVATION TEAMWORK PERFORMANCE

These are all one second or subsecond timeouts

One four second one here

If samba is ok its not the NIC, it could be congestion on routers or hubs but you have tried rsize 1024 (and wsize ??)

You might want to just bump up the NFS timeouts for those warning messages a couple of seconds. I dont think you have an actual problem. Timeouts are configurable in mount

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