Capture Windows VM memory dump in ESX

I’m working with Microsoft to identify a problem I’m seeing with LSASS, possibly related to the VSS snapshot created by our backup software. At this point, I need to be able to capture the memory state on the system, even if I can’t log into the box.

There are several ways to trigger a crash in order to collect a memory dump, but this system is a guest running in VMWare VSphere (ESX4). I asked VMWare support, and they pointed me to KB article 1009187, Generating a Windows core dump from an ESX virtual machine.

I configured my test system guest to crash and collect a memory dump on an NMI event, then used the vmdumper command to send the NMI to the guest.

It worked like a champ:

vm-crash-nmi

I verified the integrity of the dump file with dumpchk. It looks good. I’m setting the same thing up on my production guest.

Geoff
Sr. System Administrator at the University of Vermont

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