In regards to MA becoming unresponsive, you are referring to complete no access (via GUI or Putty)?
If there was jobs running at the time, these jobs will not be committed and would be marked by the JobManager as failed and will go into a "Pending" state.
Running a Full DDB Verification is a good method to validate the Backup Jobs written to the DDB (assuming Deduplication is in use) -> this will be good to verify all the Backup
- Otherwise an incremental DV is also another good option, as this will verify at the point of your last incremental DV (so it doesnt have to verify the baseline data) -> but if you are concerned with data at rest then a Full DV is good as well
Furthermore the primary concern here is why did the OS become unresponsive? A cold reboot is a temporary measure, but would recommend to engage HP to confirm whether there are any hardware issue. If the problem occurs again, I would recommend to trigger an NMI (non-maskable interrupt), which should generate a mini dump of the Server and OS, which you can then engage the necessary Vendor to review.