hi,

we run ESX 3.5 with all updates installed on a dual Intel 4 core at 2,5 GHz. with 18 Gb ram

In this ESX installation we actually run 10 server:

- 1 Citrix with 2 vcpu's and 4 Gb ram with about 20 users without problems

- many server's with minor load

- and 1 server, where we have problem's configured with 4 vcpus, 8 Gb ram, SO 2003 server

We experience problem's with this last server, sometimes this completely hang and we can't too connect to the console while esx monitor show that only 2 vcpus are busy. We have also made a test to check if the OS can use all cpu resources using 7zip compriming about 700 mb, and the esx monitor shows the server full use all 4vcpus, and like we expect we can connect to the console without problem's.

While this VM doesn't respond other's  run fine, and the general load of the ESX in under 50%.

We also think the problem can't be with IO, because the application running on work all il RAM and the esx performance monitor confirm.

Any suggestion?

Thanks in advance,

Tosolini Stefano