LVM partition shows up as /dev/hda8 under FC5.

[michaelward]

The short story: Under my vanilla FC5 installation, the new F8 installation shows up as 2 paritions /dev/hda7 & 8 under both fdisk and /dev, with none of the /dev/VoulmeXX/GroupXX stuff I've been finding described on the net. I'd like to add an entry for the F8 to my grub.conf so I can boot it.

The long story: I have been using FC5 happily for a while, and it contains all my customizations and data including: evolution stuff, emacs stuff, audio stuff, video stuff, gnome panels and scripts, and so on, and so forth, ad infinitum. I suppose some day I'll want to reapply all this stuff to a new installation of fedora, right after I put my shop back together, finish the entertainment center, the bedframes, the other furniture, in addition to writing all the stuff about math and education I'd like to get done before it flies out of my head, as well as a few extra things that would bore you even more.

In the mean time, I came across an article http://www.nilbus.com/linux/disk-copy.php that I used to make a backup of my winXP disk, with the modification that it would all be easier with a small partition of F8 on the disk so that I'd have it preinstalled whenever I copied the disk. It took a bit of figuring out how to reinstall grub to point back to my FC5 installation on the 2nd disk, but eventually I got it. Not too surprizingly, when I boot up my old trusty (and complete as far as my needs go) FC5, the F8 installation shows up as gobldygook. I know, I know ... its so much better and more functional and I really will appreciate it once I convert over to it and get to love it and ... This is the way of the world. Really makes you appreciate things that are engineered for backwards compatibility.

So now for the big question: Is there an easy way to boot the F8 installation from FC5 (without having to upgrade all the disks to LVM)?

Disk /dev/hda: 120.0 GB, 120034123776 bytes
240 heads, 63 sectors/track, 15505 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System
/dev/hda1 * 63 36665999 18332968+ 7 HPFS/NTFS
/dev/hda2 36666000 156295439 59814720 f W95 Ext'd (LBA)
/dev/hda5 36666063 127113839 45223888+ b W95 FAT32
/dev/hda6 148115583 156295439 4089928+ b W95 FAT32
/dev/hda7 127122408 127523969 200781 83 Linux
/dev/hda8 127524033 148103234 10289601 8e Linux LVM

Disk /dev/hdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 * 63 224909 112423+ 83 Linux
/dev/hdb2 * 224910 722924 249007+ 83 Linux
/dev/hdb3 722925 4948019 2112547+ 82 Linux swap / Solaris
/dev/hdb4 4948020 234436544 114744262+ 5 Extended
/dev/hdb5 4948083 69208019 32129968+ 83 Linux
/dev/hdb6 69208083 133468019 32129968+ 83 Linux
/dev/hdb7 133468083 165598019 16064968+ 83 Linux
/dev/hdb8 165598083 197728019 16064968+ 83 Linux
/dev/hdb9 197728083 234404414 18338166 7 HPFS/NTFS

- Mike

[stoat]

Originally Posted by michaelward

Is there an easy way to boot the F8 installation from FC5 (without having to upgrade all the disks to LVM)?

Hello michaelward,

The answer is yes. But LVM or no LVM, it's done the same way for both situations. GRUB can't interact with the files on an LVM physical volume. That is why your F8 system requires that separate type 83 boot partition. That separate boot partition is a standard LInux partition and contains the files that GRUB needs to create the F8 menu and boot F8 such as stage2, grub.conf, the splashscreen image, the kernel, and the initial ramdisk image.

So, all you have to do is add a section for F8 to your FC5 grub.conf. You have three ways to do it. I just laid it all out for someone else yesterday in another thread here. If you have any questions about what you read there, come back here to ask them. Also post your FC5 grub.conf.

P.S.: In your FC5 grub.conf, it's that type 83 boot partition for F8 that is relevant. That is the partition that menu commands in the FC5 grub.conf such as root and configfile should "aim at". It's probably going to be (hd0,6) in the FC5 grub.conf.

P.P.S.:

Originally Posted by michaelward

Under my vanilla FC5 installation, the new F8 installation shows up as 2 paritions /dev/hda7 & 8 under both fdisk and /dev, with none of the /dev/VoulmeXX/GroupXX stuff...

All that VolGroup and LogVol business that you where asking about does not appear in the fdisk. It does usually appear in the grub.conf as part of the root parameter for the kernel command because the kernel can deal with LVM PVs, obviously. But GRUB itself cannot.

[michaelward]

Stoat,

Thanks for your quick reply. I added the following lines to the FC5 grub.conf, the last entry I copied from the F8 grub.conf:

title Linux F8 (2.6.24.4-64.fc8 option 2a)
root (hd0,6)
chainloader +1
title Linux F8 (2.6.24.4-64.fc8 option 2b)
root (hd0,7)
chainloader +1
title Linux F8 (2.6.24.4-64.fc8 option 1)
root (hd0,6)
kernel /vmlinuz-2.6.24.4-64.fc8 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.24.4-64.fc8.img

I tried the options in the order listed (2a, 2b, 1), since I thought them most likely to work in that order. Option 2a gave the error:

root (hd0,6)
Filesystem is ext2fs, partition type 0x83
chainloader +1

Error 13: invalid or unsupported executable format.

Option 2b gave a similar error:

root (hd0,7)
Filesystem is unknown, partition type 0x8e
chainloader +1

Error 13: invalid or unsupported executable format.

I suppose I should.ve expected this since I always install grub in the master boot sector for the disk. Option 1 worked like a charm without the disadvantage of having to go through two boot menus.

Thanks for the help.

- Mike

[stevea]

Stoats other thread is fine but ...

No - it does not have to be type 0x83. Grub handles 10 differnet files system types (but not LVM).

Second and more serious comment *DO NOT* use the chainloader to boot a Linux distr owith grub installed. That's kludgey for a lot of reasons. Use the "configfile (hdN,M)/grub/gub.conf" style grub line.

title Linux F8disk
configfile (hd0,6)/grub/grub.conf


*NO* root designation.

Please note that the "(hd0,6)" is my guess for /dev/dsa7. This may not be correct based on your extended partition layout.

[stoat]

Originally Posted by michaelward

I suppose I should.ve expected this since I always install grub in the master boot sector for the disk. Option 1 worked like a charm without the disadvantage of having to go through two boot menus.

Hello again michaelward,

That's exactly right. If GRUB is installed in the master boot record, then the chainloader command doesn't work because it launches the boot partition's boot sector code, and stage1 would not be there in that case.

But that direct method that did work for you is okay and popular. Just remember that when you update the Fedora 8 kernel, you will have to recopy the new title section in order to boot the new kernel. To avoid that very minor nuisance, you can still try the configfile method also mentioned in that other thread. It doesn't care where stage1 is installed, and it is "immune" to kernel updates. But it does cause you to go through an extra splash screen or menu.

[stevea]

Ahem - going through two grub menus is NOT a disadvantage !

Here is the problem. You stick something like ....
title Linux F8 (2.6.24.4-64.fc8 option 2a)
root (hd0,6)
chainloader +1
into your FC5 grub.conf. Yes you can now boot ONE SPECIFIC F8 KERNEL>
Three weeks later when the 2.6.24.4-64.fc8 kernel has been removed by
updates then your FC5 grub.conf required manual editting.

Unless you enjoy doing manual edits with every kernel update, chainload'ing
Linux is a lousy solution. If you are not doing updates (as ins implied from
your adherence to the ancient & unsupported FC5) then you've made a poor
choice of distros.

I have 5 Linux systems and the inconvenience of manually editting grub is
NOT minor. Updates should be painless & automatic. If you don't like the
dual splashscreen you can suppress the second easily.

[stoat]

Originally Posted by stevea

Here is the problem. You stick something like ....
title Linux F8 (2.6.24.4-64.fc8 option 2a)
root (hd0,6)
chainloader +1
into your FC5 grub.conf. Yes you can now boot ONE SPECIFIC F8 KERNEL>
Three weeks later when the 2.6.24.4-64.fc8 kernel has been removed by
updates then your FC5 grub.conf required manual editting.

Unless you enjoy doing manual edits with every kernel update, chainload'ing
Linux is a lousy solution.

Hello stevea,

Are you sure that you meant to say that? I mean, I know that you know it's not required to put the kernel version in the title line like that. And the root command wouldn't change after an F8 kernel update. The chainloader command just launches the boot sector code of the F8 boot partition, so that wouldn't change after an F8 kernel update. Therefore, like configfile, the chainloader command is not affected by kernel updates. Chainloader just initiates the sequence of events one step earlier at stage1 in the boot partition's boot sector compared to configfile reloading the GRUB menu with the new grub.conf file's information. And to the eye, using chainloader to launch a Linux system appears to work just like the configfile command (presents another menu or splash screen). Sorry, but I don't get your point yet.

P.S.: Besides, michaelward didn't use the chainloader command. It didn't work because GRUB was installed in the MBR and not the boot sector of the boot partition. What michaelward ended up doing was copying the title, root, kernel, and initrd commands from the F8 grub.conf to the FC5 grub.conf which WILL have the problem you are concerned about. But I am sure michaelward knows that.

[stevea]

Oops - sincere thanks for the catch stoat ! I wasn't thinking (insufficient caffeine), or was rather thinking of direct boot without reading carefully.

My tirade #6 # should have a quote like
title Linux F8 (2.6.24.4-64.fc8 option 1)
root (hd0,6)
kernel /vmlinuz-2.6.24.4-64.fc8 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.24.4-64.fc8.img

As something NOT to put in an "other Linux" grub.conf as it requires a lot of manual maintenence.

There's nothing inherently wrong with chainloading another grub/linux instance, but it's a bit like typing "exec bash -c ..." at the command line. Why replace a perfectly good grub with another instance. Minor issue but very bad form.