How does `rm -rf` work

Question

When I try rm -rf on a directory which has a lot of subdirectories and/or files and which is mounted with SSHFS, then I takes a while to execute.

Is it normal ?

I would like to know how rm -rf works internally, at the Files System level.

Does it only remove the directory, or does it go through all directory/files ? That would explain why it so slow...

When I read the title "How works `rm -rf`? I hear Yoda's voice as the narrator. :-) — unhappyCrackers1, Jul 03 '12 at 18:25
You may be able to speed up the removal by ssh-ing into the remote system and executing the `rm -rf` there. — Brian Swift, Jul 03 '12 at 19:34
@BrianSwift Thanks for the tips, that's exactly what I did. I just wanted to be sure that I correctly understand the problem. — Charles, Jul 03 '12 at 20:54

score 6 · Accepted Answer · answered Jul 03 '12 at 18:28

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The -r switch acts exactly how its name implies: recursively. It executes the same action on each and every file and directory inside the current directory, before removing it.

So, yes, being quite slow for large (as in "with lots of different things inside") directories is absolutely normal.

One of the biggest (and most feared) signs you mistyped a rm -rf command and are actually destroying your root partition is an overly long execution time...

answered Jul 03 '12 at 18:28

Massimo

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@charles And it's going to be even worse with the `sshfs` that you mentioned, as you'll be adding in network latency, on top of any disk latency the server is experiencing while executing the `rm`. – cjc Jul 03 '12 at 18:44
that's my problem :p – Charles Jul 03 '12 at 20:56

score 2 · Answer 2 · answered Jul 03 '12 at 18:28

2

Yes, the command is recursive.

From man rm

-r, -R, --recursive

remove directories and their contents recursively

answered Jul 03 '12 at 18:28

unhappyCrackers1

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How does `rm -rf` work

2 Answers2