A few LVM questions.

blue_k · 04-05-2012, 02:59 AM

Hi,

I was just wondering do I put my boot partition in the LVM, or make a normal partition for it? Also, following the instructions for LVM included on the disk, when I generate the initrd, does this use the generic kernel, like the one in the initrd readme file, or the huge one?

Thank you

acid_kewpie · 04-05-2012, 03:05 AM

/boot would be outside of LVM. Not sure what you're referring to by the "huge one" but the initrds are used as per the matching kernel package, they aren't rebuilt during the install

blue_k · 04-05-2012, 03:13 AM

Thank you for answering. In the LVM readme, it states to run this

Code:

mkinitrd -c -k 2.6.37.6-smp -m ext3 -f ext3 -r /dev/myvg/root -L

After the install is finished. Where as the initrd readme says to do this first before running the mkinitrd command.

Code:

installpkg kernel-generic-2.6.37.6-i686-1.tgz
installpkg kernel-modules-2.6.37.6-i686-1.tgz
installpkg mkinitrd-1.1.0-i486-1.tgz

I am wondering does the LVM instructions use the kernel-generic-2.6.37.6-i686-1.tgz and the kernel-modules-2.6.37.6-i686-1.tgz packages to make it's initrd?

acid_kewpie · 04-05-2012, 03:16 AM

My apologies, I didn't realize this was in Slackware, and your profile listed CentOS 6.2. LVM should have no relation whatsoever to the running kernel though (save for LVM support which shouldn't be "interesting"

blue_k · 04-05-2012, 03:20 AM

Sorry for not making it clearer, yes I am trying to install Slackware64 13.37. So will it just use whatever kernel is running? So I would still have to go through the steps in the initrd readme to get the "generic" kernel after install correct?

tramni1980 · 04-05-2012, 03:37 AM

Hello blue_k,

There is no problem to make all your partitions on LVM, as well as /boot. Just follow the step by step instructions from the LVM-Howto (the file name is not exactly the same) file on the installation CD. If you have any further questions, do not hesitate to ask.

TommyC7 · 04-05-2012, 03:49 AM

First off, you will want /boot on it's own primary partition. The rest of Linux can be on its own Logical Partition or Primary Partition, it doesn't care but make sure /boot is on a primary partition..

Perhaps you should use the mkinitrd_script_generator:

Code:

/usr/share/mkinitrd/mkinitrd_command_generator.sh -r

If it generates the script you like, you can simply use:

Code:

$( /usr/share/mkinitrd/mkinitrd_command_generator.sh -r )
`/usr/share/mkinitrd/mkinitrd_command_generator.sh -r`

Either one should work. They will run the command the mkinitrd_command_generator script creates for you.

The command you posted will assume you want the initrd.gz for the 2.6.37.6-smp kernel and assumes the root partition is ext3, but you can make it for just about any kernel you want. I would follow the README_LVM.txt instructions. At least I did and I had a perfectly working system and that command generator even picked up the root filesystem too. No matter which kernel you choose -- just make sure it exists!

GazL · 04-05-2012, 04:50 AM

Lilo can find the initrd and vmlinuz files even if they are on a /boot that is within an LVM LV, but only if you're not doing an encrypted lvm setup. I'm not certain, but I believe with the grub bootloader these files need to be outside of LVM.

However, if you're going to leave /boot within the LVM, you might as well not have a boot lv at all and just leave the /boot directory in the rootfs. There's really no good reason to separate it in this situation.

Please bear in mind that you'll still need a primary partition to install the lilo bootcode to (unless you put it directly in the MBR - which is something I prefer not to do) and having /boot in a primary partition outside of lvm caters to this need and seems kind of a logical place to put it. It also provides you with a degree of extra flexibility (choosing to use grub or encrypted PVs in future).

You don't have to run 'generic' if you're using an initrd, but it makes sense to do so and I generally recommend running generic+initrd over the monolithic 'huge' kernels.

I'm with Tommy on this one: if you can spare a primary partition then it's a good choice.

Alien Bob · 04-05-2012, 05:02 AM

In a LVM setup, you can have your /boot directory inside the LVM, it does not have to be a separate non-LVM partition. The init script inside the initrd.gz file which you have to create, is smart enough for this to work properly.

The only case where /boot needs its own separate partition is when you do a full disk encryption of your Slackware installation (including the root partition).

Eric

TommyC7 · 04-05-2012, 01:31 PM

Heh, whoops. Sorry about telling you /boot had to have it's own primary partition. ^^

blue_k · 04-10-2012, 03:30 AM

Alright, thanks.

ricky_cardo · 04-12-2012, 07:13 PM

I did notice some weird behavior having /boot on an LVM that spanned 2 physical volumes. Lilo failed to install. When I put /boot on a separate partition outside the LVM things were cool again. I wish I captured the error I received, but it was some time ago. I was pretty sure I followed the directions to the T. Anyone else have success with 2 physical drives one LVM and /boot on there too? (again LVM on one physical drive with /boot included no problem; but when I added a 2nd physical drive lilo failed to install. I found splitting the /boot to a separate ext2 partition resolved)

Next Fresh load of Slackware I might try it again. (any pointers anyone?)