The program would have to keep a database to do what you are talking about. I think borgbackup would do what you want because it deduplicates blocks but I haven't tried. And I haven't got around to creating a usbbackup-like plugin for borg.
Understood. Thank you for the feedback.
Why do you use USB-Backup plugin if all disks are not connected via USB? The USB-Backup plugin is designed to start the job if the specified disk is plugged to the system (triggering an UDEV event to start the rsync job). You can instead use the RSync Job feature for that.
How should rsync (the tool that is doing the sync) know or guess that?
No
Thank you for your replies.
I upgraded from RPI4 with USB HDDs to x64 laptop with SATA HDDs and continued to use the same sync method. I only connect the backup HDD once a month for a manually initiated sync. In this case, is there any difference between the USB Backup and Rsync functions in OMV6?
When I rename a WinOS directory, the name of the directory changes instantly. There is no copying/moving of files that I can see. How does WinOS know or guess that it can rename the directory without creating a new directory structure and copying/moving each file to it?
Of course i know less than nothing about computers however, if I was a programmer, I might compare file+directory structures, file names, sizes, dates, attributes, etc. If the contents of two top level directories (one on the NAS drive, one on the sync/backup drive) are identical except for the top level directory name, I would update the directory name on the sync drive. Perhaps it is not possible in Linux? If true, this would be a surprise.
I understand OMV is simply using Rsync and OMV is not the author of this utility. I was hoping OMV7 might use a different utility that is more efficient and does not exhibit the "limitation" I am describing.
I use the "USB backup" function to monthly sync my NAS HDD and my backup HDD. Neither are USB connected btw.
Renaming a directory on my NAS HDD results in OMV6 creating a new directory on my backup HDD and copying/moving (can't tell which one) each file to the new directory. When that renamed near top level directory has 1TB and 100K files in it, backup time is .... much longer than it should be..
I would expect OMV to simply change the directory name on the backup HDD.
Does the "USB Backup" function in OMV7 operate as a I expect?
Came back from vacation, installed updates via OMV GUI, now same errors as OP.
"sudo omv-changebackports no" doesn't fix it. Neither does apt clean
I did this from the omv6 gui by adding the shutdown (or standby) task in SYSTEM>POWER MANAGEMENT> SCHEDULED TASKS
Did you click Save after setting the Shared Folder?
I tried to run a one-time backup. I didn't want to save it. I didn't think I needed to. I searched the OMV docs. Three hits, none of them about this backup plugin.
There are threads on your forum with backup instructions that do not mention this save requirement.. Albeit not authored by mods, mods have an opportunity to mention that requirement, and they didn't in some of the posts I read.
e.g. How to backup OMV System/configuration
Post #3 instruction followed by mod Post #4. No mention of the save requirement.
How about adding a note on the backup page stating a save is required before backup will work?
How about an appropriate error message? Maybe " You may have not clicked SAVE before BACKUP. You need to do that."
I have rebooted many times. The result is the same.
The problem is not with the cables, the data drive or my NAS computer.
If I boot the same NAS computer with Ubuntu on a USB, the data drive functions perfectly. It doesn't disconnect/disappear like it does with OMV6.
This problem started after the updates. Perhaps a coincedence? I cannot say for sure.
Denial is not a river in Eqypt! 
That's a joke... but maybe it shouldn't be one 
Happy New Year!
My OMV NAS has been running well for the past month or so until today.
The following updates were applied via the web gui:
Preparing to unpack .../libssh-gcrypt-4_0.9.8-0+deb11u1_amd64.deb ...
Unpacking libssh-gcrypt-4:amd64 (0.9.8-0+deb11u1) over (0.9.7-0+deb11u1) ...
Preparing to unpack .../openmediavault-omvextrasorg_6.3.6_all.deb ...
Unpacking openmediavault-omvextrasorg (6.3.6) over (6.3.5) ...
Preparing to unpack .../postfix_3.5.23-0+deb11u1_amd64.deb ...
Unpacking postfix (3.5.23-0+deb11u1) over (3.5.18-0+deb11u1) ...
Preparing to unpack .../openmediavault_6.9.11-3_all.deb ...
Unpacking openmediavault (6.9.11-3) over (6.9.11-2) ...
From Syslog:
Dec 30 14:26:09 ** kernel: [ 144.356936] usb 3-2: USB disconnect, device number 2
Dec 30 14:26:09 ** kernel: [ 144.357136] usb 3-2: cmd cmplt err -108
Dec 30 14:26:09 ** kernel: [ 144.357171] usb 3-2: cmd cmplt err -108
Dec 30 14:26:09 ** kernel: [ 144.357193] usb 3-2: cmd cmplt err -108
Dec 30 14:26:09 ** kernel: [ 144.357214] usb 3-2: cmd cmplt err -108
Now my USB data drive disappears after 2 minutes. Doesn't appear in LSBLK. It is as though it is physically disconnected.
Before this happens, I can access the drive over the network as expected.
This HDD is fully accessible on another Linux machine using the same interface. SMART report indicates zero issues with the drive.
My external HDD USB-SATA chip is Jmicron. Yes, I read many evil things about it. But it has been working great for a month.
I have two of these external HDD boxes. Never a single disconnect on any other of my five Ubuntu systems, only ever with OMV5 and OMV6.
How can I get it working again?
My issue ended up being caused by a bad thumb drive. Rufus flashed the drive without issue.
After I had the install issue, I ran h2testw and the drive failed.
Yes mods, I now see that I should have run h2testw before flashing the ISO as per the OMV documentation.
Hey guys,
I'm having the same problem as the OP but using OMV 6.9.8-1 (Shaitan). My testparm output is also the same as the OPs.
I did update the SMB "extra options" last week but removing all of them didn't fix this.
Looking for help to troubleshoot this further. Thanks
PS I'm an OMV and linux noob. 
-1 (Shaitan).8-1 (Shaitan)
I'd like to run a packet filtering firewall in Docker Compose.
I realize OMV6 includes a firewall but I need to filter packets for my entire network.
No luck when searching for a solution in OMV6 plugins.
Looking for suggestions that will work with OMV6 and my RPi4. Thanks!
chente , thanks for the info.
While trying to setup for a copy, only 4TB, my data drive status changed to missing again.
The drive is externally powered and I never experienced the issue over many years running OMV5. The drive is 9 months old and in good health.
I suppose it could be a hardware issue but considering it only started after switching to OMV6, I'm thinking software.
A hard data drive restart brings it back online.
Anyone have and ideas about how I can troubleshoot this sudden missing drive issue?
Thanks! I'll give this a try.
Quota begins executing on my main data drive when I mount or unmount any USB drive. I have one user and one group on my system.
I don't want Quota running because it slows me down. I need to wait 12 minutes until Quota finishes before I can, for example, run DD on the SD I just connected.
I tried to stop Quota using two methods.
1) I clicked "stop" in the "new process running" OMV6 notification.
2) I ran "sudo quotaoff -v /srv/dev-disk-by-uuid-..../".
Neither prevents it from running. It may stop Quota for a few seconds but it starts up again.
Can I stop it? If so, how?
okay. That's what I understood the first time, although later you made me doubt it.
What I'm saying is that that unit probably still has some configuration created in OMV5. And that configuration might not be fully compatible with OMV6.
Wouldn't any OMV5 config data on the backup drive be updated after the first RSYNC job with the data drive?
I think the problem is the Raspi. A Raspi has only enough electrical power to supply only one drive. Please use a self powered hub.
I wish that was the cause. Both drives are self powered.
The drive that was previously used in OMV5 is now mounted on an OMV6 system to do local rsync jobs.
Possibly some quota setting on that drive coming from OMV5 could be causing this.
If it's not very big and you can afford it I would format that drive to OMV6 and the problem should be solved. If this is a lot of work because it is a very large unit, a solution would have to be found.
Not sure I understand. Perhaps I didn't include enough information.
This is a clean OMV6 install. Not an upgrade over top of OMV5. I used a new SD for the OS+OMV6 so I could easily jump back to OMV5 if I ran into issues.
The OMV5 data drive/share remained attached to my RPI4. When I first mounted it to OMV6 and setup the folder shares, I was able to use it. I didn't change the format or file system.
The backup drive is a copy of the data drive via RSYNC in OMV5. I am now trying to run my RSYNC job to sync the data drive with the backup drive in OMV6.
Are you saying I should use OMV6 to format the backup drive before attempting to run my RSYNC job?
what format is the backup drive ntfs?
Also is the shares still there and the unmounted drive? or has are the all just missing
Data and Backup drive formats are EXT3.
I didn't test the shares after seeing the "missing" message but I again tried to mount the backup drive. This time, the data drive didn't go missing but there seems to be something not quite right.
Regardless of what physical drive I mount (even a 512MB SD card), quota begins accessing the always-connected data drive, even before I apply the change in the "Pending configuration changes" pop up.. Once I hit apply, I don't get GUI access unless I refreshed my browser window. The pending changes are to the following processes:
-collectd
-fstab
-monit
-quota
12 minutes later, quota stops and the "Pending configuration changes" pop up re-appears. The same processes as above are listed. I hit apply.
Quota runs and accesses the data drive again for another 12 minutes.
A few minutes later, quota starts, now accessing the backup drive for, you guessed it, 12 minutes ( less if I mounted a smaller drive ).
All mounted drives are accessible during this process.
There is one user and one group in my OMV6 install.
I'm waiting 36 minutes for quota to stop before I can start my backup job.
Looks like I should be ignoring the 2nd "Pending configuration changes" pop up?
Not sure if this is a linux or OMV thing but why does quota run whenever I mount another drive? Can I permanently stop this?
I
