Hello! I have a file server running Windows Server 2022 with File Deduplication enabled. It hosts a network share of about 6 TB containing roughly 2 million files. I’m trying to perform full and incremental file backups of this share.
The copy speed rarely exceeds 50 Mbps, although a system partition image from the same server copies at 700-800 Mbps.
Currently, the file share backup process looks like this: Indexing takes about 2-4 hours, and then the backup itself takes about 4 days. I would like to accelerate this process, ideally down to 10-12 hours, if possible. The server has 6 CPU cores, but the UrBackup process running on the server rarely utilizes more than 3-4% of the CPU.
What can be done to accelerate the copying process?
In addition to the question.
UrBackup server version 2.5.33
When creating a backup, I get a lot, a very large number of similar errors in the server logs
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191441” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191440” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191442” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191443” from pipe for reading ec=2
21.10.25 08:31 DEBUG HT: Linked file: “/media/backup/urbackup/fsrv[V]/251017-1929/v/30/000001.000.a3d” (id=5494773)
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191466” from pipe for reading ec=2
21.10.25 08:31 DEBUG HT: Linked file: “/media/backup/urbackup/fsrv[V]/251017-1929/v/30/rou.m3d” (id=5494778)
21.10.25 08:31 DEBUG HT: Linked file: “/media/backup/urbackup/fsrv[V]/251017-1929/v/30/r.7414.0.m3d” (id=5494780)
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191490” from pipe for reading ec=2
21.10.25 08:31 DEBUG HT: Linked file: “/media/backup/urbackup/fsrv[V]/251017-1929/v/30/100ere00.003.m3d” (id=5494860)
21.10.25 08:31 DEBUG HT: Linked file: “/media/backup/urbackup/fsrv[V]/251017-1929/v/30/100ere00.003.m3dBAC” (id=5494861)
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191491” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191492” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191493” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191494” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191495” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191496” from pipe for reading ec=2
21.10.25 08:31 ERROR Error opening file “/media/backup/urbackup/fsrv[V]/251017-1929/.b68xO+K9SCOF35cLk4Bf9Q/1191497” from pipe for reading ec=2
On the client side, there are the following errors
2025-10-17 14:46:52: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-17 14:46:52: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-17 14:46:52: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-17 14:46:52: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-17 14:48:00: ERROR: Thread exit with unhandled std::exception bad allocation
2025-10-17 14:48:00: ERROR: Fatal exception code 3765269347 at address 0x00007FFB2D4CF46C
2025-10-17 14:56:41: ERROR: Fatal exception (APPLICATION CRASHED). Crash dump written to “C:\Windows\TEMP\UrBackup\v2.0.0-20251017-144800-3488-5908.dmp”
2025-10-17 14:56:41: ERROR: Program abort (SIGABRT)
2025-10-17 19:23:19: WARNING: There are 1707040 new USN entries at ‘v:’ - reindexing
2025-10-17 19:38:35: WARNING: Stopped indexing process
2025-10-17 19:38:35: WARNING: Parent of file with FRN 281474978652030 (Name “UE-01.txt”) with FRN 281474978648921 not found. Searching via MFT as fallback.
2025-10-17 19:38:36: WARNING: Couldn’t follow up to root via Database. Falling back to MFT. Current path: comps
2025-10-17 19:38:36: WARNING: Parent of file with FRN 281474978652588 (Name “2737.txt”) with FRN 281474978652243 not found. Searching via MFT as fallback.
2025-10-17 19:38:36: WARNING: Indexing was not finished at ‘v:’ - reindexing
2025-10-19 04:02:21: ERROR: Error opening file. Errorcode: 3
2025-10-19 06:03:52: ERROR: Error looking up SID of ACE entry of file “?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1301\02\04\all\Thumbs.db”
2025-10-19 06:03:52: ERROR: Error looking up SID of ACE entry of file “?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1301\02\04\all\ReadMe.htm”
2025-10-19 06:05:30: ERROR: Error looking up SID of ACE entry of file “?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1301\02\04\Setup Files”
2025-10-19 06:05:30: ERROR: Error looking up SID of ACE entry of file “?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1301\02\04\All file”
2025-10-19 08:33:03: ERROR: Error opening file. Errorcode: 3
2025-10-19 08:49:52: ERROR: Error opening file. Errorcode: 3
And it all ended like this
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
2025-10-21 07:08:50: ERROR: Error compressing stream: 18446744073709551552 Err: Allocation error : not enough memory
The server currently has 16 GB of RAM and almost none of it is free. Apart from the file services and UrBackup, nothing else is installed on the server.
Backup is configured using several virtual sessions for different disks with different schedules. For disks of smaller size and with fewer files, everything works fine without errors, but with the largest disk there is a problem. It is possible that the issue is related to the fact that deduplication of the Windows Server 2022 file system runs once every 3 days, while the incremental backup cannot finish even within 5 days.
The debug file that was created when the program crashed —
Fatal exception (APPLICATION CRASHED). Crash dump written to “C:\Windows\TEMP\UrBackup\v2.0.0-20251017-144800-3488-5908.dmp” —
is 6 gigabytes in size.