MEPIS Community Forum

About six months ago I had some issues with partition numbering after replacing my motherboard, drives not being recognised or found by fstab, messages about bad magic numbers in superblocks. At the time I could not find a solution. The problem poked its head up again after a scheduled fsck scan at boot, and I started researching again and found a solution. All the disk and partition information is held in a cache /etc/blkid.tab. A line can be inserted into fstab to point directly to the partiton using its UUID or a simple command can be issued

will clear the cache. The tune2fsk command which ties in with this stores all instructions on the drive the details can be recovered with this command

I have updated Fsck and Fstab in the wiki, I hope this is helpful down the track for someone.

moksha, If someone has to do that do the instructions get rebuilt automatically upon a reboot?;..... just curious. Jerry

Using just UUID in Mepis is not a good idea, because if you use the correct command to upgrade, it comes up with, "unrecognized bootloader"
in other words the system has not got a clue as to what the legacy bootloader is, (yes it will boot but for how long) it expects to find Grub2.
Hopefully within the next few hours I will post the correct commands to use UUID but it will mean installing Grub2. so as the system does know what it is doing,

The main reason for using persistent naming is because the drive name never changes as it does now in Mepis,
the easy way is to run "dpkg-reconfigure linux-base" but that presents a problem, as the system does not recognise the legacy bootloader in Mepis, yes it will run and it will boot, but for how long is anybodys quess.
http://dl.dropbox.com/u/53792173/grub-edit10.png
so you have to install Grub2 first, which you would do like this.
disable the Mepis repo in Synaptic, reload search for grub-common and upgrade it.
In Konsole as root,
apt-get update
rm -rf /boot/grub
apt-get purge grub-gfxboot
apt-get install grub2 os-prober desktop-base

when the above is complete you can now enable persistent naming
dpkg-reconfigure linux-base
reboot and re-enable the Mepis repo

If you are talking about tune2fs the instructions 'live' in the drive and can be seen with tune2fs -l, so in a chainloaded boot setup the tune2fs commands are at a hardware level and do not care about reboots simply partition mounts. I believe and I have yet to try it that the tune2fs -c xx /dev/sdx instruction would survive an OS reinstall - linux that is. The instructions are probably in the form of set bits on the partiton, that increment with each boot.
The blkid -g command flushes the /etc/blkid.tab, and creates a backup, this is where the kernel and fstab looks for mount info at boot (not quite sure how that process works yet), so yes it survives rebooting.

Just trying to get some clarity here, the UUID is not being used in menu.lst but after in fstab. However as I note in the wiki entry blkid -g may also be used which means a UUID does not need to be used at all. Thank you I will go back and make sure no confusion can arise from what I have written in the wiki.