VM loses connectivity when copying files to it

[ematelyan]

Hello,

I'm trying to troubleshoot an issue were having with our VMs, and I'm looking for some guidance on how to even start with it.

Physical Host: HP DL360e Gen8

Version: ESXi 5.1

We only have 5 VMs on it at the moment.  This is a newer company, so we're just getting our feet wet.

Basically, we have a few Windows Server 2008 R2 VMs, and it appears that anytime we try to copy a large number of files to one of the VMs over the network, it loses it's network connectivity, and has to be rebooted.  The VM doesn't necessarily crash or anything, but it can't be connected to by remote desktop, or pinged.  If I go into VSphere, I can still connect to the console, but it has to be rebooted before the network connectivity comes back up.  We've replicated it several times, and this is definitely the process to cause it.  If I copy one large file to it, it's not a problem, just when we copy several smaller files.  Any ideas on what could be causing this?

[jdptechnc]

What type of storage are you using, and what type/speed of connectivity are you using?  You might be causing high disk latency in the guest OS such that it is unable to access its drives, which can cause the system to just stop responding.  If that is happening, you might see some disk errors or controller errors in the system event log of the guest.

Also, if you are using software iSCSI on the same uplinks that your VMs are using, check the utilization of those nics and see if you're saturating them.