Linux hangs randomly

Hello,

At first, I had a Linux VM (CentOS) connected via NFS to a NAS. Randomly, Linux guest hanged on with the following message on kernel log:

Feb 12 20:44:31 srv-doohan kernel: [ 2940] 0 2940 24532 313 3 0 0 sshd

Feb 12 20:44:31 srv-doohan kernel: [ 3625] 0 3625 24532 294 2 0 0 sshd

Feb 12 20:44:31 srv-doohan kernel: [ 4301] 0 4301 24547 335 3 0 0 sshd

Feb 12 20:44:31 srv-doohan kernel: [ 4662] 0 4662 24530 304 1 0 0 sshd

Feb 12 20:44:31 srv-doohan kernel: [ 4978] 0 4978 24530 302 1 0 0 sshd

As it happened several times, I created another Linux VM with another distribution (Ubuntu), connected to same NAS, and I got the same message:

Feb 15 08:59:59 srv-pedrosa kernel: [234285.030860] [16883] 0 16883 18492 25 2 0 0 sshd

Feb 15 08:59:59 srv-pedrosa kernel: [234285.030868] [17120] 0 17120 18460 27 2 0 0 sshd

Feb 15 08:59:59 srv-pedrosa kernel: [234285.030876] [17355] 0 17355 18417 26 0 0 0 sshd

Feb 15 08:59:59 srv-pedrosa kernel: [234285.030884] [17595] 0 17595 18443 27 2 0 0 sshd

Feb 15 08:59:59 srv-pedrosa kernel: [234285.030892] [17834] 0 17834 18450 24 2 0 0 sshd

Each VM has a different kernel version: CentOS -> 2.6.32 | Ubuntu -> 3.2.0

Googling, I found it could due to vmmemctl. Has anyone had this before?

My ESXi hosts are at version 4.1 Update1, and this behaviour happens on all of them. Maybe it could due to be on an old ESXi version?

Thanks in advance,