You can permanenty delete any data using
shred utility. It overwrites the specified file(s) repeatedly, in order to make it harder for even very expensive hardware probing to recover the data.
In most cases I use the next options:
shred -fuz <file(s)>
If you want to see output, you can add
Here’s all options:
-f, --force change permissions to allow writing if necessary -n, --iterations=N overwrite N times instead of the default (3) --random-source=FILE get random bytes from FILE -s, --size=N shred this many bytes (suffixes like K, M, G accepted) -u, --remove truncate and remove file after overwriting -v, --verbose show progress -x, --exact do not round file sizes up to the next full block; this is the default for non-regular files -z, --zero add a final overwrite with zeros to hide shredding --help display this help and exit --version output version information and exit