# Incorrect Free Space Warnings
**URL:** https://forum.duplicati.com/t/incorrect-free-space-warnings/19728
**Category:** Support
**Created:** [December 18, 2024, 4:31pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728 "2024-12-18T16:31:30Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [December 18, 2024, 4:31pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/1 "2024-12-18T16:31:30Z")
Everything has been working fine in my Duplicati instance until around 19 days ago when I started getting these warnings:
```plaintext
2024-12-18 03:03:34 +00 - [Warning-Duplicati.Library.Main.Operation.FilelistProcessor-BackendQuotaNear]: Backend quota is close to being exceeded: Using 930.028 GB of 45.000 GB (10.540 GB available)
```
The thing is, the location I am backing up to is 2 TB in size and there are 777 GB of space remaining. The log message does not make sense.
My Duplicati instance is currently on v2.1.0.2\_beta\_2024-11-29 installed within a [Docker container](https://hub.docker.com/r/linuxserver/duplicati/). I can see by running `df -h` inside my container I have these mount points with various amounts of free space:
```plaintext
Filesystem Size Used Avail Use% Mounted on
/dev/loop2 45G 34G 11G 76% /
tmpfs 64M 0 64M 0% /dev
shm 64M 0 64M 0% /dev/shm
shfs 14T 9.7T 4.0T 71% /source
/dev/sdf2 1.9T 1.1T 777G 59% /TowerBackup
/dev/loop2 45G 34G 11G 76% /etc/hosts
tmpfs 7.8G 0 7.8G 0% /proc/acpi
tmpfs 7.8G 0 7.8G 0% /sys/firmware
tmpfs 7.8G 0 7.8G 0% /sys/devices/virtual/powercap
```
Evidently, Duplicati is checking for free space on `/etc/hosts (/dev/loop2)` rather than my configured location of `/TowerBackup (/dev/sdf2)`.
This is not a problem with Duplicati being able to “see” my `/TowerBackup` mount because the actual backup works fine and I am able to see restore points for every day. I have a few questions:
- Why has this only just started happening when I have not changed my configuration? Duplicati has been working fine for well over a year before this.
- Why is Duplicati able to correctly use the `/TowerBackup` for the backup but not for the free space validation?
- What can I do to fix this?
Thanks!
---
### Author:  [@marceloduplicati](https://forum.duplicati.com/u/marceloduplicati)
#### Post date: [December 18, 2024, 5:32pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/2 "2024-12-18T17:32:12Z")
Hi @pepperywasp, I assume that you are using “file” backend as destination.
There was a change on that backend on specifically on quota estimation that might be the source of this discrepancy that triggers the warning. The part that is responsible for the backup is unchanged so that explains why the actual backup its working.
> - What can I do to fix this?
You already did bringing it up. Thank you.
I have raised an [issue](https://github.com/duplicati/duplicati/issues/5791).
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [December 18, 2024, 5:54pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/3 "2024-12-18T17:54:22Z")
> [@pepperywasp](#):
>
> Why has this only just started happening when I have not changed my configuration?
Flaw in big code change. [File backend reports incorrect quota on Linux & MacOS #5733](https://github.com/duplicati/duplicati/issues/5733#issuecomment-2515030052)
> [@pepperywasp](#):
>
> Duplicati has been working fine for well over a year before this.
and old one still would, but you got new one.
> [@pepperywasp](#):
>
> Why is Duplicati able to correctly use the `/TowerBackup` for the backup but not for the free space validation?
Code has various parts. Only quota part broke.
> [@pepperywasp](#):
>
> What can I do to fix this?
> [@Duplicati Warning - BackendQuotaNear](https://forum.duplicati.com/t/duplicati-warning-backendquotanear/19601/2):
>
> For a workaround, you can set the advanced option to disable the warning:
>
> `--quota-disable=true`
Or you can carefully run a Canary test release, or you can wait for fix in future Beta or Stable.
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [December 18, 2024, 8:32pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/4 "2024-12-18T20:32:36Z")
> [@marceloduplicati](#):
>
> I have raised an [issue](https://github.com/duplicati/duplicati/issues/5791).
Thank you I have subscribed to the issue.
> [@ts678](#):
>
> Flaw in big code change. [File backend reports incorrect quota on Linux & MacOS #5733](https://github.com/duplicati/duplicati/issues/5733#issuecomment-2515030052)
Thank you, I’ll keep an eye out for this making it to a Beta release and will post back on whether this fixes my issue.
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [December 21, 2024, 5:54pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/5 "2024-12-21T17:54:06Z")
> [@Duplicati Warning - BackendQuotaNear](https://forum.duplicati.com/t/duplicati-warning-backendquotanear/19601/2):
>
> For a workaround, you can set the advanced option to disable the warning:
>
> `--quota-disable=true`
Unfortunately, I still get the warning using this option set to true.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [December 21, 2024, 6:16pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/6 "2024-12-21T18:16:01Z")
> [@pepperywasp](#):
>
> using this option set to true.
Where did you put the option? If in job `Advanced options`, you also need to check it, like below:
If it doesn’t do what it says, maybe it’s a bug, but you can also see if `quota-size` option helps it.
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [January 3, 2025, 10:42am UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/7 "2025-01-03T10:42:46Z")
> [@ts678](#):
>
> Where did you put the option?
I set the option here:
With limited time to deal with this I have decided to automatically bin any e-mails with this (and only this) warning and wait for a beta release that fixes the root cause.
Thanks for your help.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [January 3, 2025, 10:41pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/8 "2025-01-03T22:41:17Z")
> [@pepperywasp](#):
>
> wait for a beta release that fixes the root cause.
The problem with that plan is the root cause doesn’t get fixed until someone figures it out.
Reading the size from the wrong partition got fixed, but `quota-disable` still doesn’t work.
Or at least it doesn’t stop that warning on the latest Canary release, so it deserved a look.
My guess about the code change that broke the `quota-disable` workaround was posted:
[Duplicati Warning - BackendQuotaNear](https://forum.duplicati.com/t/duplicati-warning-backendquotanear/19601/11)
Test used Linux with a 1 MB tmpfs filesystem, and a file made using dd and /dev/urandom.
When a Warning began, I tried quota-disable=true and quota-size=1TB. What worked was
quota-warning-threshold=0
```plaintext
--quota-warning-threshold (Integer): Threshold for warning about low quota
Set a threshold for when to warn about the backend quota being nearly exceeded. It is given as a percentage, and a warning is generated if the amount of available quota is less than this percentage of
the total backup size. If the backend does not report the quota information, this value will be ignored.
* default value: 10
```
where math sounds like warning would need an available quota of less than zero to go off.
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [January 3, 2025, 11:01pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/9 "2025-01-03T23:01:48Z")
> [@ts678](#):
>
> The problem with that plan is the root cause doesn’t get fixed until someone figures it out.
> Reading the size from the wrong partition got fixed, but `quota-disable` still doesn’t work.
I believe the root cause of me getting the error in the first place is (as you say) the issue of using the wrong partition for the size and it appears to be fixed in [#5734](https://github.com/duplicati/duplicati/pull/5734).
Of course, the `quota-disable` issue should be fixed as well. But I don’t think that is the root cause for me.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [January 3, 2025, 11:16pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/10 "2025-01-03T23:16:13Z")
> [@pepperywasp](#):
>
> But I don’t think that is the root cause for me.
It might be the root cause for
> [@pepperywasp](#):
>
> I still get the warning using this option set to true.
but if you’d rather bin e-mails, fine. If you try new workaround attempt, feedback would be nice.
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [January 23, 2025, 7:30am UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/11 "2025-01-23T07:30:59Z")
This appears to be fixed in the latest beta.
---
### Author:  [@SatiricalCrab1182](https://forum.duplicati.com/u/SatiricalCrab1182)
#### Post date: [April 21, 2026, 1:52am UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/12 "2026-04-21T01:52:43Z")
Hi, sorry to resurtrect this old thread, but I thought I’d add that I just had this issue on verion 2.3.0.0\_stable\_2026-04-14, with it falsely coming up with a warning saying I was out of space in the backend quota.
I’m running on Unraid in a docker and was able to add the string / optoin to disable th backend quota, and the error / warning has now gone:
Thanks for the tip, and hgopefully it will get fixed premanently somehwere down the line.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 21, 2026, 2:53pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/13 "2026-04-21T14:53:09Z")
> [@SatiricalCrab1182](#):
>
> warning saying I was out of space in the backend quota.
Please show the warning (as was done in original post), especially since
> [@SatiricalCrab1182](#):
>
> I’m running on Unraid in a docker
is a bit unusual, and I don’t know if the devs have that. More info will help.
Original post has other examples. The job log `Complete log` has as well:
```plaintext
"TotalQuotaSpace": 999618043904,
"FreeQuotaSpace": 24240660480,
"AssignedQuotaSpace": -1,
"ReportedQuotaError": false,
"ReportedQuotaWarning": false,
```
from a Windows backup. Looks about like I expect, but check your system.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 21, 2026, 3:15pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/14 "2026-04-21T15:15:50Z")
You can also get a “fresh” reading without a backup by using [BackendTester](https://docs.duplicati.com/duplicati-programs/command-line-interface-cli-1/backendtester).
You can add `--reruns=1` if you like, to shorten it. Sample quota test at end:
```plaintext
[11:09:47 707] Checking quota...
[11:09:47 709] Free Space: 23.46 GiB
[11:09:47 709] Total Space: 930.97 GiB
[11:09:47 710] Checking DNS names used by this backend...
[11:09:47 710] Unittest complete!
```
You would have to do this from `docker exec` or similar inside the container.
While there you can also try your favorite available tools, e.g. `df` for values.
EDIT 1:
I’m also noticing that specifics of the destination weren’t said. That’s needed
because it’s what gives the numbers that I’m asking for which may be wrong.
---
### Author:  [@SatiricalCrab1182](https://forum.duplicati.com/u/SatiricalCrab1182)
#### Post date: [April 22, 2026, 12:20am UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/15 "2026-04-22T00:20:27Z")
hey @ts678 ,
so this is the warning message:
`"2026-04-16 04:00:46 -04 - [Warning-Duplicati.Library.Main.Operation.FilelistProcessor-BackendQuotaNear]: Backend quota is close to being exceeded: Using 3.043 TiB of 30.000 GiB (13.225 GiB available)"`
I have attached the full log for this backup too.
[backup log.zip](https://forum.duplicati.com/uploads/short-url/rHNlOmaKD7g9mW8Ibjb9Y8ei5ZR.zip) (1.7 KB)
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 22, 2026, 2:16am UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/16 "2026-04-22T02:16:52Z")
What is the Destination type, how big do you think it is, and what shows that?
Because the 3 TB number looks plausible (and is internally kept by Duplicati),
I’d guess 30 GB coming back from somewhere is wrong? Is anything 30 GB?
Long ago, a `mono` bug looked in the wrong partition. Are there several there?
If it’s not on local folder but on some sort of remote, what type of remote is it?
---
### Author:  [@pepperywasp](https://forum.duplicati.com/u/pepperywasp)
#### Post date: [April 23, 2026, 9:14pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/17 "2026-04-23T21:14:36Z")
Interestingly, I (i.e. the OP) started seeing these errors again around the same time that @SatiricalCrab1182 resurrected this thread.
I get exactly the same error (with slightly different numbers) as my original post:
```plaintext
2026-04-23 04:02:36 +01 - [Warning-Duplicati.Library.Main.Operation.FilelistProcessor-BackendQuotaNear]: Backend quota is close to being exceeded: Using 869.336 GiB of 55.000 GiB (16.063 GiB available)
```
And looking at my version `2.3.0.0_stable_2026-04-14` container’s mount points I see:
```plaintext
Filesystem Size Used Avail Use% Mounted on
/dev/loop2 55G 38G 17G 71% /
tmpfs 64M 0 64M 0% /dev
shm 64M 0 64M 0% /dev/shm
shfs 14T 14T 651G 96% /source
/dev/sdf2 1.9T 1.1T 837G 56% /TowerBackup
/dev/loop2 55G 38G 17G 71% /etc/hosts
tmpfs 7.8G 0 7.8G 0% /proc/acpi
tmpfs 7.8G 0 7.8G 0% /sys/firmware
tmpfs 7.8G 0 7.8G 0% /sys/devices/virtual/powercap
```
So again, Duplicati is looks like it is checking for free space on `/etc/hosts (/dev/loop2)` rather than my configured location of `/TowerBackup (/dev/sdf2)`.
Is it possible that there has been a regression?
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 23, 2026, 10:55pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/18 "2026-04-23T22:55:02Z")
> [@pepperywasp](#):
>
> Is it possible that there has been a regression?
This needs dev input, but it looks like 2.3.0.0\_stable\_2026-04-14 rewrote it.
>
>
> This PR adds checks for free temporary space when starting the server and when r…estoring.
>
> On systems that have limited space in the temp folder a warning will now be shown.
>
> This is intended to capture issues on some Docker systems where /tmp is mounted in memory instead of being disk backed.
>
> It will also detect the issue on other systems that are space constrained.
The old FileBackend.cs called an elaborate internal GetDrive() which is now
replaced by a call to the new GetFreeSpaceForPath(). Suspicious code is at
>
which seems to explain why your quota check is for /.
/dev/loop2 use looks odd to me, but it may not matter.
Thanks for the details. That might have led to the bug.
Old bug in `mono` (now gone) could not have reverted.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 24, 2026, 1:53pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/19 "2026-04-24T13:53:17Z")
Pursuing the BackendTester idea posted above, on Linux Duplicati 2.3.0.0.
This is in a VirtualBox VM with a shared folder that’s on the Windows host.
```plaintext
$ duplicati-backend-tester --reruns=1 /media/sf_VirtualBox_shared_folder/tester
...
[09:43:07 633] Checking quota...
[09:43:07 636] Free Space: 6.185 GiB
[09:43:07 637] Total Space: 28.865 GiB
$ df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 297M 1.3M 296M 1% /run
/dev/sda3 29G 22G 5.5G 80% /
tmpfs 1.5G 0 1.5G 0% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/sda2 512M 6.1M 506M 2% /boot/efi
VirtualBox_shared_folder 931G 915G 16G 99% /media/sf_VirtualBox_shared_folder
tmpfs 297M 140K 297M 1% /run/user/1000
$
```
It looks like bug did as predicted, giving space for / rather than the path I gave.
EDIT 1:
2.2.0.3\_stable\_2026-01-06 on the same test seems to be reading correct path:
```plaintext
[10:13:12 952] Checking quota...
[10:13:12 956] Free Space: 13.415 GiB
[10:13:12 956] Total Space: 930.967 GiB
```
---
### Author:  [@SatiricalCrab1182](https://forum.duplicati.com/u/SatiricalCrab1182)
#### Post date: [April 25, 2026, 7:21pm UTC](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728/20 "2026-04-25T19:21:30Z")
Hey, sorry for the delay in my response.
So, the backup destination location is a local unassigned disk on the unraid server; it’s 14TB with about 7TB free. It’s mapped to the path /backups in Duplicati, from /mnt/disks/.
The 3TB could be the size of the source and desination of the media backup:
I have 2 other backup schedules running, but the sizes are very different.
[Next page](https://forum.duplicati.com/t/incorrect-free-space-warnings/19728.md?page=2)