Common Issues

This section describes issues which are seen in the field more often, possible reasons and mitigations.

Slow backups due to high sync times

When encountering very slow incremental backups even on low or no changes in M365 items (e.g. a mailbox), check for min/max/avg sync times of items in the logs. Navigate to the VB365 log folder C:\ProgramData\Veeam\Backup365\<ORGANIZATION>\<JOB NAME> and run the following PowerShell command to search in the logs for sync times which are over 1 second.

select-string "Sync time: [^0]" *

This is an example output:

PS C:\ProgramData\Veeam\Backup365\Logs\<ORGANIZATION>\<JOBNAME>> select-string "Sync time: [^0]" *
...
Job.<JOB NAME>_2022_04_14_08_59_59.log:2732:[14.04.2022 09:00:08]   59 (8132)  Sync time: 143.7938527
Job.<JOB NAME>_2022_04_14_08_59_59.log:2737:[14.04.2022 09:00:08]   49 (4600)  Sync time: 324.8092703
...

Usually sync times are way below one second but of course there can be a few exceptions. However, if you get a lot of results from above query with values far greater than 1 seconds, you should double check your environment, e.g. if you’re not using a direct connection for your proxies. In case of doubt, open a support ticket with Veeam for assistance.