RHEL 5.3 Hangs when yum, rpm or df -h is run

[protos78]

We have Red Hat Enterprise Linux Server release 5.3. For the last two weeks, the server started not to respond "df -h", rpm and yum requests. Here is an example of yum package installation.

yum install sysstat
Loaded plugins: rhnplugin, security
Setting up Install Process
Parsing package install arguments
Resolving Dependencies
--> Running transaction check
---> Package sysstat.x86_64 0:7.0.2-3.el5 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

================================================== ============================== Package Arch Version Repository Size
================================================== ==============================Installing:
sysstat x86_64 7.0.2-3.el5 rhel-x86_64-server-5 174 k

Transaction Summary
================================================== ==============================Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)

Total download size: 174 k
Is this ok [y/N]: y
Downloading Packages:
sysstat-7.0.2-3.el5.x86_64.rpm | 174 kB 00:00
Running rpm_check_debug
Running Transaction Test
Killed
(I killed the process. I waited for more than2 hours. This should be done instantly. )

If I run, df -h, it shows some of the mounted drives and hangs. Waited for more than 12 hours, nothing happened. I checked the system log, and there is no error message. It would be great if you can tell me how I can diagnose the issue?

Thanks,

[protos78]

I solved the issue. In case, someone finds this website through search engines, here is the solution:

THe problem was stale nfs mounts. I first checked /etc/mtab and removed the stale nfs mounts. Then, commented stale nfs mounts at /etc/fstab. Restarted nfs client. Mounted drives again. Rebuild rpm databases. Bingo, it works!!!