About a week ago I transfered all files from one hard drive to the other to move my distro to a newer hard drive. I booted my computer up with a live cd and entered the shell as root. I mounted my new hard drive as /mnt/new and mounted my old hard drive as /mnt/old. I then proceeded to copy the files the only way I knew how.

# cp -Rv /mnt/old /mnt/new

I did it verbosely so I could see when it was done from across the room as I watched television.

Anyways. The copy was successful. Every file was copied to the new drive. So I shut down the pc, took out the old hard drive and set the new one as the main. I then proceeded to boot up.

First problem... no grub. So I used a floppy to install grub to the MBR. No problem.

I continued on a booted up my debian. I got all the way to the KDM login screen. I tried to login but the screen flickered and then went back to the KDM screen to login again. I swear I must have logged in 20 times before i stopped...

I then went to command line and i was able to login as user and root... Hmm... so I viewed my hard drive to make sure all the files were there:

# ls -al /

This is when I noticed... Every folder and every file is now owned by user root and group root. I supposed this was the problem and i decided i didnt want to fool with it again, so I just did a clean installation from scratch.


Now I am at a point again where I need to copy over more files from one hard drive to another (different machine). How can I copy all the files over to a new hard drive yet leave the permissions untouched?

cd <source> ; tar -cf - . | (cd <dest> ; tar -xvf -)

Where <source> and <dest> are the source and destination directory locations. Example:

cd /mnt/hda1 ; tar -cf - . | (cd /mnt/hdb1 ; tar -xvf -)

This is faster, because one thread is reading from the source, and another is writting to the destination. Simple but effective example of multithreading. Speed is ~1.8x as fast as regular copying, and even faster when the source & destination are on separate devices & controllers.

And this will leave all file and directory permissions unchanged?

cp also has an option -p to preserve permissions

# cp -Rpv /mnt/old /mnt/new