Hello all.  I am opening a support case for this, but thought I may bounce this by here, maybe someone will have a quick answer.

We have multiple EV 9.0 servers in our directory.

(we recently have gone through a chain of upgrades too, on all of them, from 7.0 SP1 to 7.5, to 8.0, to 9.0)

Anyway, all EV servers are working fine, except weird behavior on one of them - PST Migrator task on this server cannot handle archiving more than One PST at a time (the task is set up to migrate up to 5 PSTs simultanesouly)

There are a bunch of PSTs sitting in the collector share. They get backed up. Migrator copies them to the Migrator location and they change status to Migrating.  Then only one of them remains in Migrating status, the rest turn into Migration Failed status.

If I change the failed ones manually back to Ready to Migrate status, they fail again.

This continues until that first PST is finished being archived (goes to Completing or Complete).   I then can manually change the failed ones to Ready to Migrate, and they all become Migrating. But then they all fail again, except one.   And the cycle continues.

As a workaround I set the Migrator task to only process 1 pst at a time. At least this way I don't have to manually babysit the failures.  I set them all to Ready to Migrate, and they eventually get processed, one at time.

All these PSTs are various sizes, some are even 265KB (empty ones) and even those fail to be migrated when the migrator task is set up for multiple simulatneous migrations.

Also when the PSTs fail, I see these entries in the event log: