Mount /usr on new partition?

R List · n00b Joined: 16 Sep 2004 Posts: 6

Hi, new user here.

This is more of a general question: I tried out Gentoo and other distros. Thus I have some 4Gb partitions on my disk. I have settled on Gentoo now as my everyday distro, however I foresee problems with diskspace and I don't want to reinstall all the stuff.

My question: Can I create a new file system on one of the other partitions and copy everything under (gentoo)-/usr to that partition (cp -r *) , remove everything under the old /usr and automount the new partition as /usr ?

It seems logical to me but will I screw up something, e.g. file permissions etc?

Thanks in advance

BlackEdder · Posted: Thu Sep 16, 2004 12:10 pm Post subject:

You can, just use your cp flags carefully to make sure you keep the right permissions. Also before you empty the /usr dir you can mount the new one over it and check if everything still works. Then when you are possitive it works unmount your new usr and emty the old one + remount the new one (it might be wise to empty the old dir while booted from a livecd, but it is probably not necessarily.)

TheRAt · Veteran Joined: 03 Jun 2002 Posts: 1580

I would suggest using tar for the job. Something like:

BlackEdder · Posted: Thu Sep 16, 2004 12:48 pm Post subject:

I'm sorry, but why use tar?? It serves no purpose at all in this case except to use cpu cycles..
Just copy with the -rp flag and permissions should be kept ->

R List · n00b Joined: 16 Sep 2004 Posts: 6

OK, I did a copy with the arguments -rpP and it seems to work this far (but the call is still out on that...)

But I did something potentially stupid and am now confused: After having copied /usr to another partition I edited /etc/fstab and moreover renamed the old /usr to /usrOLD to have as backup if anything went wrong. I then was unsure what would happen if I rebooted in an orderly fashion and instead of doing that, by heavenly inspiration, pressed the reboot button. Then when the system is up I have no /usrOLD (filesystem is ext2) . There is now a discrepancy between what du and df says:

du says the old partition (i.e. except for /usr) uses 500M out of 4G and /usr (the new partition) uses 1,6G

df says old partition uses 2,1G (which happens to equal 1,6G + 500M) and the new 1,6G.

So, to me it seems df and du gives contradictory answers. Am I interpreting them incorrectly or is the filesystem screwed up? Is /usrOLD which dissappeared when I rebooted taking up space which only shows up in df but not in du???? I find it hard to believe that df would include the space used by /usr for the old filesystem ( = / )

I am confused. fsck didn't show anything.

TheRAt · Veteran Joined: 03 Jun 2002 Posts: 1580

When you altered the fstab entry, did you create a /usrOLD dir ??

This will be required for it to mount correctly...
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R List · n00b Joined: 16 Sep 2004 Posts: 6

BlackEdder · Posted: Fri Sep 17, 2004 8:14 am Post subject:

well I think the move to usrOld somehow didn't work. This means that the new partition is mounted over the old dir (which is like I said no problem) This means the 500 mb is still taken, but you can't access it except by umounti /usr and so can't du (therefore the discrepancy between du and df) I suggest you test it for a few days and when you decide the new usr dir works you do:

R List · n00b Joined: 16 Sep 2004 Posts: 6