df command is dangerous for scripting - it gives incorrect results if you want to check for free space.

[Jim-JMCD]

Discussed in https://github.com/microsoft/WSL/discussions/11953

^{Originally posted by **Jim-JMCD** August 24, 2024} In scripts, if you going to check for free space, before writing, you can't use the standard **df $PWD** or **df $write_target** as a check. According to the sequence below in WSL2, a script checking for free space will fail. The script write until its filled up all the free space on the laptop/PC C:\ drive. This laptop only had WSL in its C:\ location. If its a company server it could be a potential big problem for sysadmins. ``` $ df -h $PWD Filesystem Size Used Avail Use% Mounted on /dev/sdc 1007G 5.3G 951G 1% / $ df -h /mnt/c Filesystem Size Used Avail Use% Mounted on C:\ 931G 815G 116G 88% /mnt/c $uname -a Linux fred 5.15.153.1-microsoft-standard-WSL2 #1 SMP Fri Mar 29 23:14:13 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux ``` - The first **df** tells me I have 951 GB of free space to play with in my WSL2 home directory. - The second **df** tells me I have 116 GB of free space where WSL2 and everything else lives on the C:\ drive - The reality is WSL has only 116 GB cause its VHD will dynamically grow until used up everything on the C:\ drive This was reported earlier but the folks didn't realize the consequences https://github.com/microsoft/WSL/discussions/9757 Having WSL on a non-OS drive [D:\] is interesting the drive size (1007G) is the same as previous but doesn't resemble any drive on both installations. ``` $ df -h $PWD Filesystem Size Used Avail Use% Mounted on /dev/sdc 1007G 2.5G 954G 1% / $ df -h /mnt/d Filesystem Size Used Avail Use% Mounted on D:\ 1.9T 1.6T 280G 85% /mnt/d $ df -h /mnt/c Filesystem Size Used Avail Use% Mounted on C:\ 112G 54G 59G 48% /mnt/c $ echo $PWD /home/jjm bob@HP01:~$ df -h | grep /mnt/ | grep -v none C:\ 112G 54G 59G 48% /mnt/c D:\ 1.9T 1.6T 280G 85% /mnt/d G:\ 1.9T 1.7T 178G 91% /mnt/g S:\ 932G 700G 232G 76% /mnt/s T:\ 932G 900G 33G 97% /mnt/t $ uname -a Linux HP01 5.15.153.1-microsoft-standard-WSL2 #1 SMP Fri Mar 29 23:14:13 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux ```

[github-actions[bot]]

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Download and execute [collect-wsl-logs.ps1](https://github.com/Microsoft/WSL/blob/master/diagnostics/collect-wsl-logs.ps1) in an **administrative powershell prompt**: ``` Invoke-WebRequest -UseBasicParsing "https://raw.githubusercontent.com/microsoft/WSL/master/diagnostics/collect-wsl-logs.ps1" -OutFile collect-wsl-logs.ps1 Set-ExecutionPolicy Bypass -Scope Process -Force .\collect-wsl-logs.ps1 ``` The script will output the path of the log file once done. If this is a networking issue, please use [collect-networking-logs.ps1](https://github.com/Microsoft/WSL/blob/master/diagnostics/collect-networking-logs.ps1), following the instructions [here](https://github.com/microsoft/WSL/blob/master/CONTRIBUTING.md#collect-wsl-logs-for-networking-issues) Once completed please upload the output files to this Github issue. [Click here for more info on logging](https://github.com/microsoft/WSL/blob/master/CONTRIBUTING.md#8-collect-wsl-logs-recommended-method) If you choose to email these logs instead of attaching to the bug, please send them to wsl-gh-logs@microsoft.com with the number of the github issue in the subject, and in the message a link to your comment in the github issue and reply with '/emailed-logs'.

[Jim-JMCD]

WslLogs-2024-08-25_06-44-02.zip

[github-actions[bot]]

The log file doesn't contain any WSL traces. Please make sure that you reproduced the issue while the log collection was running.

Diagnostic information

``` Detected appx version: 2.2.4.0 Found no WSL traces in the logs ```

[Jim-JMCD]

WslLogs-2024-08-28_09-44-59.zip

Alternatively you can check it for yourself by running the commands in the order of the original post. Its simple stuff.

[github-actions[bot]]

Diagnostic information

``` Detected appx version: 2.2.4.0 ```