Rsync as root to the file system root

halfpower · 01-25-2020, 01:30 PM

I want to merge the contents of a directory with the base of the file system with rsync. I ran the command

Code:

sudo rsync -lrtva my_dir/ /

This bricked the server. I retried the same task on another server by running the command

Code:

sudo cp -d my_dir/path_N/file_N /path_N/file_N

on every file. This server did not brick.

What did I do wrong? Do the two methods not produce the same result? Note that "my_dir" contains arbitrary system critical files.

ehartman · 01-25-2020, 01:41 PM

Quote:

Originally Posted by halfpower

Note that "my_dir" contains arbitrary system critical files.

If you overwrite /sbin, /bin, /lib or /etc "critical" files, you will brick the system. /usr is a bit less critical as its mostly the multi-user and/or networking part of the O/S.

berndbausch · 01-25-2020, 05:35 PM

Quote:

Originally Posted by ehartman

/usr is a bit less critical as its mostly the multi-user and/or networking part of the O/S.

Shudder. On Debian (and elsewhere):

Code:

# ls -l /
...
lrwxrwxrwx  1 root root     7 Jan 20 09:49 lib -> usr/lib
lrwxrwxrwx  1 root root     9 Jan 20 09:49 lib32 -> usr/lib32
lrwxrwxrwx  1 root root     9 Jan 20 09:49 lib64 -> usr/lib64
lrwxrwxrwx  1 root root    10 Jan 20 09:49 libx32 -> usr/libx32
...

A brick recipe.

halfpower · 01-26-2020, 10:06 AM

Quote:

Originally Posted by ehartman

If you overwrite /sbin, /bin, /lib or /etc "critical" files, you will brick the system.

The command sudo rsync -lrtva my_dir/ / appears to be deleting something in the destination directory. My understanding had been that rsync would merge directories and not delete unless the option --delete was included.

edit: I suspect this is actually an issue with permissions and ownership due to the -a option.

ehartman · 01-26-2020, 12:13 PM

Quote:

Originally Posted by berndbausch

Shudder. On Debian (and elsewhere):

The OP was using Slackware, which doesn't have that problem.
But yes, in Debian (etc.) it can be even more fatal to rsync user files to /

pan64 · 01-26-2020, 12:20 PM

It just depends on what was overwritten (copied into /). As root you can easily destroy anything.
When you copy into /path/to/some/where [obviously] you won't destroy your root filesystem.

Try --dry-run if you wish.
During boot you may see a message about what was missing or corrupted...