Linux

I deleted my root directory in an attempt to delete a file that was starting with the character "/". A crash of konqueror had left such impossible file in some subdirectory of /tmp. As root I played with some regular expresssions to delete it, but only managed to delete my root directory. Not completely (as the excessive disk activity made my soon realize my mistake), but sufficiently beyond repair.

To see how much disk space you have left use df -h The h flag is for "human readable". Otherwise you get the size in 1k blocks. To see how much space a directory is using type du -hs h is again for human readable and s means summary - meaning only the total size is given. Without s you get recursively the size of every file below the directory.

I wanted to copy a whole encrypted partition over the network into a file. You can execute many commands via ssh, but occasionally there are problems to direct the output where you want it. E.g. the "more" command doesn't output to standard out when used via ssh. You need to use "less" to get the file content displayed locally (at least using a RedHat 8 remote machine). With dd you cannot use the "dd if=input of=output" syntax but you need the "dd < input > output" syntax.