What is the difference between snapshot and backup in Job Details, and what is the top line for?

[qox]

In the Job Details Window, each VM takes two lines, snapshot and backup. And each has a different elapsed time. What is difference between them? And what is the elapsed time of the root line on top for?

I tried to sum up the snapshot elapsed times and the backup elapsed times separately. None of them equalled the time in the root line.

The screenshot is of a job of a VM-backup policy that includes 4 Linux VMs.

 

[L_BR]

The first line (Job ID 68324 AKA Parent Job) is the query being run to determine what must be backed up. This job will start first, and end last.

The Snapshot Jobs are Netbackup issuing Vcenter Snapshot commands for the VM in question. This job will start before the backup job and finish after the backup job is complete. You can see the first Snapshot job starting at 12:45:03 ends 8 seconds after the first Backup Job finishes at 12:48:31. This is because The Snapshot job will send a Snapshot delete request to Vcenter and wait for the response before finishing the job.

The backup jobs should be self explanatory. They're the actual backup job for the VM. Which will normally start last and finish first. 

[qox]

And how to understand the elapsed times of the first snapshot, which is 00:03:36?

[L_BR]

For some reason my reply to you keeps getting deleted. Your Snapshot starts, runs for ~2 min, then your backup starts and runs for 1min 29 seconds. That totals 3min 29 seconds. The extra 7 seconds is probably processes connecting with vcenter and vcenter deleting the snapshot and returning the status code to Netbackup.

[qox]

Wait a minute..

The difference between the starts of snapshot and backup is 1:59 minutes.

The difference between the ends of snapshot and backup is 0:08 minutes.

The duration of backup is 1.29 minutes.

The total of the above is 3:36.

This means that backup is part of snapshot.

[L_BR · Accepted solution]

That is correct. Like I said. The very first job is the Parent Job. The first snapshot job is called the child job. If you read the detailed status, you will see that Netbackup sends a snapshot request to Vcenter. Once Vcenter has confirmed the snapshot has taken place, it returns a status code to Netbackup. Netbackup then starts another child job, the backup job. 

One the backup job is complete. The Snapshot job will then send a snapshot delete request to Vcenter. Once it returns a status code 0, the snapshot job will complete.