how to enable NFS trace

Iyyappan · 08-22-2014, 01:37 AM

We have RHEL 5.10. From DB server a partition is exported via NFS to 3 NFS client server (SAP)

Very often SAP application shows errors that NFS server not reachable or its hung.

But in NFS client/server, in messages logs, there is no such errors.

Not sure how SAP application alone reports the errors, but am not able to see them in NFS server or client side..

tcpdump o/p

07:42:02.549679 IP server01.nfs > server02.773845761: reply ok 1368 read
07:42:02.549698 IP server01.nfs > server02.538976288: reply ERR 1368
07:42:02.549705 IP server02 > server01.nfs: . ack 266209 win 7626 <nop,nop,timestamp 1933690912 2111305698>
07:42:02.549766 IP server01.nfs > server02.538976288: reply ERR 1368
07:42:02.549772 IP server01.nfs > server02.1952804468: reply ERR 1368
07:42:02.549775 IP server02 > server01.nfs: . ack 268945 win 7626 <nop,nop,timestamp 1933690912 2111305698>
07:42:02.549804 IP server01.nfs > server02.1626262330: reply ERR 1368
07:42:02.549850 IP server01.nfs > server02.825761840: reply ERR 1368
07:42:02.549854 IP server02 > server01.nfs: . ack 271681 win 7626 <nop,nop,timestamp 1933690912 2111305698>
07:42:02.549871 IP server01.nfs > server02.1462452580: reply ERR 1368
07:42:02.549896 IP server01.nfs > server02.72831084: reply ERR 1368
07:42:02.549899 IP server02 > server01.nfs: . ack 274417 win 7626 <nop,nop,timestamp 1933690912 2111305698>
07:42:02.549983 IP server01.nfs > server02.4286075787: reply ERR 1368
07:42:02.550683 IP server01.nfs > server02.732516835: reply ERR 1368
07:42:02.550696 IP server02 > server01.nfs: . ack 277153 win 7626 <nop,nop,timestamp 1933690912 2111305698>
07:42:02.550758 IP server01.nfs > server02.3400406261: reply ERR 1368
07:42:02.550774 IP server01.nfs > server02.780585953: reply ERR 1368
07:42:02.550778 IP server02 > server01.nfs: . ack 279889 win 7626 <nop,nop,timestamp 1933690912 2111305699>
07:42:02.550800 IP server01.nfs > server02.2761732424: reply ERR 100
07:42:02.559450 IP server02.790622977 > server01.nfs: 132 read fh Unknown/01000

In some forum, they say its related to network.

Is it possible to enable trace for NFS client partitions..

TB0ne · 08-23-2014, 04:56 PM

Quote:

Originally Posted by Iyyappan

We have RHEL 5.10. From DB server a partition is exported via NFS to 3 NFS client server (SAP) Very often SAP application shows errors that NFS server not reachable or its hung. But in NFS client/server, in messages logs, there is no such errors. Not sure how SAP application alone reports the errors, but am not able to see them in NFS server or client side..

In some forum, they say its related to network. Is it possible to enable trace for NFS client partitions..

Since you don't tell us what the "SAP Application" is, what do you think we'll be able to tell you? If you're not seeing errors from the Linux side of things, and NFS isn't reporting errors, then (quite obviously), the SAP application is doing that reporting, and whatever conditions THEY say are 'errors' are getting logged.

Your best bet is to call the SAP Application vendor and/or Red Hat support...since you're PAYING FOR RHEL, right??? They can help you run a very detailed trace and analysis of things, and help you diagnose the problem. Have you applied the latest patches to RHEL 5.10's NFS??