"Backing up System Reserved (SYSVOL) partition failed"

Hello everyone,

First of, I would like to thank @uroni and everyone else involved in developing and maintaining this great software!

We’ve got a QNAP TS-873 as the backup server (v2.4.12) and 5 Windows (10 and 7) clients (v2.4.10) backing up to it, doing only image backups.

3 of the clients (all of which are in “Internet Mode”) have a recurring error (Backing up System Reserved (SYSVOL) partition failed. Image backup failed) each time a backup occurs (whether it’s Full or Incremental) and we can’t figure out how to fix it (although the backup always succeeds after a retry, but it’s annoying and the 2 other clients don’t have this problem).

Things we’ve tried:

  1. Disable IPv6.
  2. Disable any Offload / Green Ethernet / Any Other “Network Optimization” options in the Network Adapter settings in Device Manager.
  3. Change “Transfer Mode” settings (Raw / Hashed).

I’ll post the debug log of one of the clients (Windows 7 64-bit).

Any help would be greatly appreciated!
Thanks again!

EDIT: We’ve just updated the server to v2.4.13.
EDIT2: Attached another log from a different client (Windows 10).

debug.log (131.6 KB)
debug.log (379.0 KB)

Would really appreciate any help with this.

Here’s a server log snippet of a failing backup:

2020-09-13 16:51:44: Establish timeout: Deleting internet client “Dentist-PC”
2020-09-13 16:52:02: Authed+capa for client ‘Dentist-PC’ (encrypted-v2, compressed-zstd, token auth) - 1 spare connections
2020-09-13 16:55:44: Starting scheduled full image backup of volume “C:”…
2020-09-13 16:55:44: Backing up SYSVOL…
2020-09-13 16:55:44: Starting scheduled full image backup of volume “SYSVOL”…
2020-09-13 16:55:44: Connecting to target service…
2020-09-13 16:55:54: Connecting on internet connection failed. Service=0
2020-09-13 16:55:54: Establishing internet connection failed. Service=0
2020-09-13 16:55:54: ERROR: Connecting to ClientService of “Dentist-PC” failed: Getting MBR for drive SYSVOL failed
2020-09-13 16:55:54: Establishing internet connection failed. Service=0
2020-09-13 16:55:54: Connecting to ClientService of “Dentist-PC” failed: Error sending ‘running’ (2) ping to client
2020-09-13 16:55:54: Error sending ‘running’ (3) ping to client
2020-09-13 16:56:04: Establishing internet connection failed. Service=0
2020-09-13 16:56:04: ERROR: Connecting to “Dentist-PC” for image backup failed
2020-09-13 16:56:04: Updating statistics…
2020-09-13 16:56:04: Updating image stats…
2020-09-13 16:56:04: Updating file statistics…
2020-09-13 16:56:04: Done updating statistics.
2020-09-13 16:56:04: Establish timeout: Deleting internet client “Dentist-PC”
2020-09-13 16:56:04: Connecting to ClientService of “Dentist-PC” failed: Error sending ‘running’ (2) ping to client
2020-09-13 16:56:04: Error sending ‘running’ (3) ping to client
2020-09-13 16:56:05: ERROR: Backing up System Reserved (SYSVOL) partition failed. Image backup failed
2020-09-13 16:56:05: Time taken for backing up client Dentist-PC: 21s
2020-09-13 16:56:05: ERROR: Backup failed