I've got 22GB free - unsure how to proceed .

Version: 8.2.11 (x64)
wxWidgets Version: 3.3.1

on Win 10 Pro.

I just force quit BOINC and all it's sub-processes and restarted, this time it seems to have recognized some space, Disc tab says:

- free, available to BOINC: 5.33 GB
- free not available to BOINC: 20.77 GB

Is that ok, or do I need to do something for it to recognize more space as being available?

Is that ok, or do I need to do something for it to recognize more space as being available?

Should be fine for MCM tasks. If you ever run tasks from a project that needs a lot of disk space such as LHC or CPDN to to Options>Computing Preferences>Disk and untick all the options except the amount of disk space you want to guarantee is kept free. Of the three options, the most restrictive is the one that will apply. To give an idea of what is used, CPDN on my box with one 4 core task running is using 6.27GB of disk space.

Hello,

I have the same problem. It started after upgrading BOINC to version 8.2.11 (wxWidgets Version 3.3.1). I have not found a solution yet. I'd be happy if someone could help.

Problem:
BOINC incorrectly reports insufficient disk space, even though there is ample free space. The error appears in both the Notices and Event Log, preventing tasks from being downloaded or processed for LHC@Home and World Community Grid.

BOINC’s computing preferences are set to:
Use no more than 40.00 GB
Leave at least 20.00 GB free
Use no more than 95.00% of total disk space

The disk has 444 GB free out of 1.81 TB total.

Affected Projects:
LHC@Home: Server message: "Theory Simulation needs 7629.39 MB more disk space. You currently have 0.00 MB available."
World Community Grid: Server message: "Mapping Cancer Markers needs 500.00 MB more disk space. You currently have 0.00 MB available."

Steps Taken to Resolve:
Reinstalled BOINC 8.2.11 and verified the correct data folder was selected. This alone did not help.
Manually emptied the data folder, restarted BOINC, and rejoined the projects. The folder refilled, but the error persisted.
Changed computing preferences to only be limited by "Use no more than 40.00 GB". Also didn't help.

Operating System: Windows 11 Pro (10.0.26200 Build 26200)

Thanks in advance!

In reply to Grodan's message of 17 May 2026:

Hello,

I have the same problem. It started after upgrading BOINC to version 8.2.11 (wxWidgets Version 3.3.1). I have not found a solution yet. I'd be happy if someone could help.

Problem:
BOINC incorrectly reports insufficient disk space, even though there is ample free space. The error appears in both the Notices and Event Log, preventing tasks from being downloaded or processed for LHC@Home and World Community Grid.

BOINC’s computing preferences are set to:
Use no more than 40.00 GB
Leave at least 20.00 GB free
Use no more than 95.00% of total disk space

The disk has 444 GB free out of 1.81 TB total.

Affected Projects:
LHC@Home: Server message: "Theory Simulation needs 7629.39 MB more disk space. You currently have 0.00 MB available."
World Community Grid: Server message: "Mapping Cancer Markers needs 500.00 MB more disk space. You currently have 0.00 MB available."

Steps Taken to Resolve:
Reinstalled BOINC 8.2.11 and verified the correct data folder was selected. This alone did not help.
Manually emptied the data folder, restarted BOINC, and rejoined the projects. The folder refilled, but the error persisted.
Changed computing preferences to only be limited by "Use no more than 40.00 GB". Also didn't help.

Operating System: Windows 11 Pro (10.0.26200 Build 26200)

Thanks in advance!

Update: After changing computing preferences to only be limited by "Leave at least 40.00 GB free" at least World Community Grid downloaded tasks. I will post again if LHC@Home does not download in the future.

Nonetheless, there seems to be a bug in the current BOINC Version. My original computing preferences shouldn't cause BOINC to recognize 0MB free.

Your problem is here:

BOINC’s computing preferences are set to:
Use no more than 40.00 GB
Leave at least 20.00 GB free
Use no more than 95.00% of total disk space

Currently you are limiting BOINC to a maximum of 20 GB no matter what the other 2 settings are.

* You need to change the second setting (20 GB max) to something a lot smaller like 1 GB or 0.1 GB.

This will allow BOINC to use 38 GB of the 40 (40*0.95=38) you have allowed it to use of the free space on the drive.

You can also increase the first setting from 40 GB to a larger setting such as 50 GB.

In reply to Dr Who Fan's message of 17 May 2026:

Your problem is here:

BOINC’s computing preferences are set to:
Use no more than 40.00 GB
Leave at least 20.00 GB free
Use no more than 95.00% of total disk space

Currently you are limiting BOINC to a maximum of 20 GB no matter what the other 2 settings are.

* You need to change the second setting (20 GB max) to something a lot smaller like 1 GB or 0.1 GB.

This will allow BOINC to use 38 GB of the 40 (40*0.95=38) you have allowed it to use of the free space on the drive.

You can also increase the first setting from 40 GB to a larger setting such as 50 GB.

Thanks for the reply but that is not my understanding of the information in the help pages, see below.

Use no more than N GB: Limit the total amount of disk space used by BOINC.
Leave at least N GB free: Limit disk usage to leave this much free space on the volume where BOINC stores data.
Use no more than N% of total: Limit the percentage of disk space used by BOINC on the volume where BOINC stores data.
Source: https://github.com/BOINC/boinc/wiki/Preferences#disk-and-memory

You are reading it incorrectly!
The limiting factor is Use no more than N GB change that to 40 GB like I mentioned in my original reply. This OVERRIDES all other settings.

As it says EXACTLY in the wiki:
Use no more than N GB: Limit the total amount of disk space used by BOINC.