Urbackup Server Migration Errors

Hello @uroni,

I am trying to migrate our backup data in UrBackup from a Windows 2019 server (INI-DROP4) to a windows 10 pro machine (INI-DROP5). The WIN 10 Pro machine has two external drives mirrored in storage spaces to have 5 TB of available space as the D:\ drive of that system. The drive for the Server 2019 system is a 2 TB external drive.

Based on the information below, what do we need to do to fix the errors and\or ensure all of our data is migrated over to the new system?

If we see symlink\hard link errors and data is missing in the migration destination folder, should we run the remove_unknown.bat file or should we resolve the errors first?


The destination of the migration is [\Ini-drop5\D\Backup](file://Ini-drop5/D/Backup) and this is what is in the migrate_storage_to file in the following location on INI-DROP4 C:\Program Files\UrBackupServer\urbackup.

I configured a service account with Administrative access that is being used as the service account for the Urbackup service on all the clients and the backup server. I also added the same account to the migration destination server.


We are receiving errors like the following on repeat while the migration is running. The log file is attached.

  • 2021-11-04 18:44:32: ERROR: Error creating hard link at “D:\Backup\INI-VHOST1.directory_pool\wx\wxKa5qqj481635802519515222375$R0UDBR1.xlsx” to “\Ini-drop5\d\INI-VHOST1\210923-1704\D$RECYCLE.BIN\S-1-5-21-2381945198-1594288983-1562607873-1108$RGI9UHC.xlsx”
  • 2021-11-04 18:46:50: ERROR: Copying backup id 4017 path 211031-1717 of client “INI-VHOST1” failed.
    Log file:
    urbackup20211105 - Copy.7z (733.0 KB)

Other findings:

I also noticed that in the folders for the clients in the destination of the migration, there are files that say _incomplete at the end of them and there are folders that are just missing data. I assume that this has something to do with symlinks, but I am not sure.
_incomplete files screenshot

  • The migrate_storage_to.done file is present in the C:\Program Files\UrBackupServer\urbackup on the source backup server (INI-DROP4)
  • The migration is sitting at 0% in the in the activities page.

What process are you using for the migration?

Is it this one?


Are you migrating it will it is running new jobs?

One recommendation (which I did on two occasions), is just to setup the new backup server as a second backup server, and then, when you’ve gotten a full set of backups on the new server, stop using the old one, and just keep it around a little while for the historical backups.

You can use this method when you don’t want to take things down first.


Thank you for the recommendation!

Yes. I am currently using the procedure you linked for the migration and am migrating while jobs are running.

Did you decide to not use the migration tool because you had problems with it?

I used the other method because it was easier to ensure that there was no downtime based on the size of the backups being performed. My client was less nervous with this approach, because there was no data in flux at any time.