Tmpfiles.d — difference between `x` and `X` options

tmp

I'm configuring tmp cleanup on CentOS 7. The docs for tmpfiles are a little unclear to me when explaining the difference between the X and x options in tmp.conf. The difference according to the docs is that with the X option,

Unlike x, this parameter will not exclude the content if path is a directory, but only directory itself.

I'm not sure how to interpret this.

Basically I have a directory which lives in /tmp and which I don't want to be deleted (including its contents). For this, is it enough to add a line

x /tmp/myspecialdir

to /usr/lib/tmpfiles.d/tmp.conf?

Best Answer

I also found this very confusing. Here's a quick example. I think x versus X becomes useful if you have a deep tree inside a particular directory and you want to delete some and not all directories.

Here's my exclude.conf: root# cat /etc/tmpfiles.d/exclude.conf d /tmp/testdir 0755 root root 1s x /tmp/testdir/*

Now, I create some directories: # mkdir /tmp/testdir/a ; mkdir /tmp/testdir/b; mkdir /tmp/testdir/ab

# ls -lrt /tmp/testdir/ total 0 drwxr-xr-x. 2 root root 6 Sep 1 12:55 a drwxr-xr-x. 2 root root 6 Sep 1 12:55 b drwxr-xr-x. 2 root root 6 Sep 1 12:55 ab Run clean

#systemd-tmpfiles --clean exclude.conf

Check

# ls -lrt /tmp/testdir total 0 drwxr-xr-x. 2 root root 6 Sep 1 12:55 a drwxr-xr-x. 2 root root 6 Sep 1 12:55 b drwxr-xr-x. 2 root root 6 Sep 1 12:55 ab

Now, if do X /tmp/testdir/*, I get the same result. Then, if I have x /tmp/testdir/b, then it excludes the 'b' directory from the cleanup.

#systemd-tmpfiles --clean exclude.conf

# ls -lrt /tmp/testdir/ total 0 drwxr-xr-x. 2 root root 6 Sep 1 12:55 b Also, X /tmp/testdir/b shows the same behavior. However, X /tmp/testdir/ and x /tmp/testdir will delete all the sub directories inside testdir but will keep testdir.

I would suggest to test the settings before you put it in place. I the man page could be little more clearer.

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