After running Disk Usage Analyzer on the file system, I am looking for ways to remove unneeded files on my Live USB.

1. Firstly, is there anything I can do about the files in the casper archive? For example, I noticed that there exists a directory /rofs, which I'm sure stands for read-only file system, the one stored in the read-only casper file, so I can't removing anything in it. Specifically, I removed LibreOffice yet /rofs/usr/lib/libreoffice takes up 222 MB of precious storage, as does Thunderbird and a bunch of other things.




2. What can I clear regarding the apt program files. /var/lib/apt/lists takes up 115 MB, and /var/cache/apt (not the archives directory) is 139 MB. The /var/cache/apt folder is made up of several ~35 MB files, and I don't know if they are all necessary:

   
   
   

   ubuntu@ubuntu:/var/cache/apt$ du -ah
   
   4.0K    ./archives/partial
   
   0       ./archives/lock
   
   28K     ./archives
   
   4.0K    ./typescript
   
   34M     ./srcpkgcache.bin
   
   31M     ./srcpkgcache.bin.ifDvIA
   
   34M     ./pkgcache.bin.3IHVIK
   
   32K     ./pkgcache.bin.h2Zwz7
   
   36M     ./pkgcache.bin
   
   133M    .
   
   




3. I already clear browsing data regularly when I use chrome, so I don't think I have to deal with that much. However, I see that there are cache folders for other programs, and I wish to know if there is a safe way to remove the cache.

Generally, my question revolves around why I have only less than 300 MB on my 4.0 GB USB thumb drive when I only use it for browsing and simple development in python.

Your help is appreciated.