Pfsense VM stunning during veeam replication

[JamesVA]

I'm using veeam 9.5 to replicate a live pfsense VM to another datastore on the same host.  During that process, pfsense VM becomes stunned for about 30 seconds and completely unresponsive.  I know my underlining storage sucks - it's a test setup… The pfsense vm is 4gb RAM, 8gb vmdk - so I figure snap shotting that should be a pretty quick task...

source datastore - 7200rpm disk
destination datastore - iscsi attached zfs raidz storage, 4 sata disks.  no physical switches are involved between storage and esxi.

Has anyone run into similar issues?

Thanks in advance!