[PVE-User] Kernel crash debug, how?

[Stanislav German-Evtushenko]

Proxmox VE 2.3 (latest updates) crashes from time to time (possibly
during VM snapshot backup but not sure yet). I did manage to read on
only the tail of crash log so I don't know what was the cause. The
first part of log was out of the screen and that log wasn't written to
any of log-files.

The questions are:
1) what is the right way for Proxmox VE to get this log to file?
2) if get the log to fle is not easy then what is the right way to get
crash dump and and to look inside it?