GPT + LILO: limitations?
 

Hi,

My current build server is a multiboot machine with quite many different installations on it. Here's what the hard disk looks like:

/dev/sda1 is the common swap partition for each system. /dev/sda2 is the "control system", running Slackware 14.1 64-bit. /dev/sda3 is running Slackware 14.0 32-bit, /dev/sda5 Slackware 14.0 64-bit. /dev/sda6 has Slackware 14.1 32-bit, /dev/sda7 Slackware 14.1 64-bit. The other partitions are for different combinations of version (14.0, 14.1, 14.2), architecture (32-bit, 64-bit) and scenarios (server install without GUI vs. desktop). LILO is configured via the installation on /dev/sda2.

Today I got a new build server, and I would like to copy that setup to my new machine. I'd also prefer to add four extra partitions. As far as I remember, I've reached fdisk's possible limit of logical partitions (correct me if I'm wrong). Normally, GPT partitioning allows me to go beyond this limitation (up until 64 partitions, IIRC).

I just tried the gdisk (GPT) partitioning scheme + LILO combination, and it works on this machine.

So now I'd like to know the eventual limitations of LILO with this kind of thing. Can I configure something like twenty partitions and then access them via LILO?

Cheers,

Niki

If I remember from reading the various docs that come with Slackware, lilo doesn't always work with a GPT system, so it looks like you got lucky. I've read that elilo is a version of lilo that is intended to work better with GPT.

Note: I use MBR so anything I'm saying in the preceding paragraph is theoretical, not actually tried by myself.

If you don't mind the (slight amount of) added work of making a initrd for each OS, you could stick with MBR and use LVM to get any number of partitions. I've got two Slackware installs running off the same LVM which is in turn in a LUKS partition, so I confirm that LVM works. :) Note: the boot partition can't be within an LVM, but with care, it is possible to have one boot partition that is used by multiple Linuxes: you make sure the kernel and initrd for each OS has a unique name and update lilo accordingly.

edit: adding a second hard drive is another way to get more partitions. ;)

Looks like this setup is working. I partitioned the 500 GB hard disk using gdisk (GPT) with no less than 18 partitions. I thought about LVM for a moment, but since I have some clearly defined needs - in terms of partition size - from the start, no need for an additional layer of abstraction, the more so since LILO seems to play nice with the current partitioning scheme.

My doubts mainly concerned the number of different systems LILO can address. I guess such extreme multiboot setups are quite rare. Well, for the time being everything seems to work OK.

Cheers,

Niki

You can boot from LVM if you wish - I do it here. Have a look at the README_LVM.TXT in the top level directory.

Niki,

I don't think on a GPT disk you need extended partitions, but maybe that is needed to be able to boot from a MBR with lilo. Did you do without that partition (/dev/sda4)?

I am asking as, a while ago I changed my setup from MBR+LILO to GPT+elilo/refind (i.e. eufi). Before the 'bios' eventually went into eufi-mode I found that the old MBR was still used, at least the system was still booting, but this was done by lilo instead of elilo. For elilo you'll need a separate fat partition, so I wouldn't try GPT+elilo if you do not want to go to eufi-like booting.

No extended partitions here. GPT doesn't suffer from all these braindead DOS limitations. I'm currently busy reinstalling all the systems, partition by partition. So far, everything from /dev/sda2 to /dev/sda6 included boots fine. Things look good.

And here's the end result. Partitioning:

Bootloader:

Cheers,

Niki

Wait... Kiki, did you use an EF02 BIOS Boot Partition at all or direct boot from a /(root)?

No EFI here. On some motherboards you can use GPT partitioning and install LILO like you would do on "classic" (e. g. fdisk) partitioning. I don't know exactly how or why, but as long as it works, I don't care.

Cheers,

Niki

HI, whats-the-difference-between-gpt-and-mbr-when-partitioning-a-drive/ gives an overview that GPT under GNU/Linux systems should have no problem creating unlilmited partition but it is only windows which is limited to 128 partitions.

The development of LILO ends at December 2015 lilo alioth.

Unless, a team from slackware can maintain it.

lilo just works.

I normally have 20 or more logical unit per lvm per hard disk, even tested snapshot lvm with slackware. LVM works with Slackware GNU/Linux since 12.0.

with lilo you need no EF02 BIOS Boot Partitio.

As long as MBR: protective is present, lilo should work fine

I fail to see why anyone is concerned about this. OEMs aren't making any more non-UEFI machines, and I suspect LILO will continue to work for the existing BIOS ones without much (or even any) ongoing maintenance. There have been several fairly long periods of time where there weren't any new LILO versions and it continued to "just work", as you say. Plus, the last official release was just a couple of weeks ago! I don't consider code to be dead simply because a maintainer (not even the original one) is warning that they're going to quit working on it. But maybe I'm more pragmatic... I also don't consider a project to have started when there's just a manifesto and no code (even if it's coming soon!) ;)

Since LILO is not going to need any work (and I won't just ticker with it for no good reason), I volunteer to take over. Consider it maintained.