Well it seems that those UUIDs are busting my silicons again. Here is the situation:

My PC consists of a hard drive rack with several removable hard drives (SATA 80GB) on which I install various operating systems. I have XP, Ubuntu - Production (for which I am careful to document any changes), Ubuntu - test (which was cloned from Ubuntu - Production and which I use to test things before I install them on Production). Inside the PC is a fixed SATA 320GB formatted with NTFS. The 320GB drive is accessible from all OSes and auto mounts and appears on the Ubuntu desktop as "Quite Large" which is the NTFS label. Until...

I recently installed 7.10 on another drive to try out the upgrade process to 8.04 LTS. Other than the upgrade taking a long time because of all the users hitting the server and the fact that 8.04 broke my marginal xsane scanner capability (I think) no big deal. Until...

I booted the PC with my Ubuntu - Production disk installed. The "Quite Large" icon representing the NTFS drive was not on the desktop. I can select Places; Computer; Quite Large; and mount it. However, I cannot access it with gnome-commander. "No permission to mount" error even though it appears to be mounted.

After a couple of hours of booting different configurations, comparing files such as /etc/fstab, testing, tweaking, cussing etc. I tried to manually mount the NTFS drive from the command prompt on the Production disk. I got a message to the effect "can not find UUID blah blah blah".

I then compared the fstab files. On Production and Test (remember this was cloned from Production) the UUDI for /dev/sdb1 (my NTFS partition) was the same. On the "newest" Ubuntu install it was different. It seems that the installation process "discovered" the 320GB drive, assigned it a new UUID and wrote the UUID to the drive. I copied the "new" UUID to fstab on the older installs and the automatic mounting works as before and the icon is on the desktop.

I have had some previous run ins with UUIDs when doing backup and restore between hard drives. I was advised to "just say no to UUIDs" however, the process to do this was not explained. I tried removing them from fstab and the grub boot list and managed to get things rather messed up.

Can someone please explain to me how to dispense with UUIDs for good? If it is possible?

TIA,

Ken

Same as always - use device designations; /dev/sda3 (whatever is appropriate). For all my systems I eventually dispense UUID/LABEL, as I am always screwing around with drives/partitions. It was introduced because of the libata namespace change (when /dev/hda became /dev/sda) - for the convenience of the distro devs/maintainers, not the users.
Ubuntu installs usually mess with the UUID on swap as well ...

Well I gave it a try again. I think I should go back to vi (or perhaps CP/M - bet that would run like a scalded dog on a Pentium 4). Anyhow gedit showed me entries in fstab which looked like this:

So I simply deleted the UUID= expression which of course gave me:

In effect I commented out my entire fstab I think this is what happened the last time I played with removing UUIDs. Word wrap - wonderful NOT!

I have also removed UUIDs from /boot/grub/menu.lst and all is working well. Thanks for motivating me to finally fix this!

I can see how UUIDs would be helpful in some cases where data storage is removed and replaced. However, in my case I am removing and replacing the OS disk. The data disk always is in the same place and I do not need different installs of the OS calling it different UUIDs.

Regards,

Ken

Neither UUIDs nor sd/hd identifiers are reliable. The real problem in this case is that Ubuntu inherits a serious bug from Debian, which still fails to handle hard drives correctly if they are connected to more than one controller. The solution is easy but it takes a bit of work. You have to look in /dev/disk and use IDs to identify your partitions, both in fstab and in in GRUB. You would identify a partition on a SATA drive as:

/dev/disk/by-id/scsi-(etc. - just copy the information from the /dev/disk directory)

Thanks jay73. At the moment I only have a single controller - 2 SATA connections on the motherboard - and I only use 2 drives at any given time. I will keep your advice in my reference file in case I ever need to add more storage or create a more complicated configuration.

Regards,

Ken

Okay, first thing to understand--any line which begins with # is a comment. The line is ignored.

You can't just delete the UUID= field. The first field is the field which tells the computer where the heck this file system is. This can be UUID=sfasdfw or it can be /dev/sda1 or it can be something else, but it has to be SOMETHING.

The line which starts with "#" is JUST a comment. It's a helpful comment, since it tells you which device the next line is talking about, but it is for YOUR benefit, not the computer's. The computer ignores it.

If you want to modify your fstab, you can delete the UUID= field, but you must replace it with something else, like /dev/sda1.

So this has nothing to do with word wrap.