master server Failed due to Hyper-V snapshot backup

HI I am using netbackup 7.7.1 in windows server 2012 r2

I have one master and two media servers in which master server is a Hyper-V machine.

I have Configured Hyper-V Snapshot backup for all Hyper-V machines in a Physical machine, My master server is also one of the Hyper-V machines in that physical machine. while during the tie of backup master server unavailable for few hours andall of sudden the hyper_v machine which is having master server was restarted meanwhile all of the backup jobs are failed at that particular time. what is the reason for this. Is this a better pratice to install master server in Hyper-V machine and taking backup of that particular master server with the same master server.