# General Linux Tips

# Server Investigations

## Low Disk Space

Running out of disk space can cause all sorts of havoc.

Get list of directories & files that are taking up the most space. This checks from the current dir, but replace the `*` with a specific dir to check it specifically.

`du -hsx * | sort -rh | head -10`

## Find Duplicate Processes

If you have a shell script that may pile up with too many duplicate processes running, you can find which scripts have duplicates running with this command:

`ps aux | sort --key=11 | uniq -c -d --skip-fields=10 | sort -nr --key=1,1`

## SELinux

If you're using SELinux, the following command will list things getting blocked by SELinux to help you find potential misconfigurations:

`grep -E 'setroubleshoot|preventing' /var/log/messages`

# Cleanup Invalid MP3 Files

1. Install mp3check  
    
    1. Probably already available in your distro. Example: `sudo apt install mp3check`
2. Scan a directory of MP3 files with: `mp3check -erBR3 "SOME_DIR"`
    1. This only scans files and reports issues, it does not make any changes
    2. This is recursive. Remove the lowercase `-r` to not dive into subdirectories
    3. `-B` causes it to allow variable bitrate files. If your player doesn't support VBR, remove this flag to identify files that are VBR. Note: mp3check cannot convert VBR to CBR, you need tore-encode for that.
3. Fix files with command: `mp3check -r3 --cut-junk-start --cut-junk-end "SOME_DIR"`
    1. This will write changes to the files stripping out the invalid chunks. The file modified time will be updated

**Notes:**

- The recursive option does not appear to work properly and only seems to go 1 directory deep
- The Dirname handling seems unusual. You may need to use a /\* at the end for it to scan the entire dir

**Example cleanup output:**

[![image.png](https://www.wswapps.com/uploads/images/gallery/2025-08/scaled-1680-/S7EWXBUHp1qZhgEH-image.png)](https://www.wswapps.com/uploads/images/gallery/2025-08/S7EWXBUHp1qZhgEH-image.png)