Is this an appropriate partitioning scheme for multi booting several distros? MBR+LVM

tauro_kpo · 07-26-2012, 02:46 PM

Hello everyone,

I've been reading, asking, and trying to find the most suitable partitioning scheme for my multi booting 2 TB hdd, and probably this is the definitive one (or close). I want to hear your opinions, and I have some questions also. Now let's take a look:

Code:

    N°   type      label   FS      Size
|--sda1 primary    grub2   ext4    32 MB
|--sda2 primary    swap             2 GB
|--sda3 logical    distros        400 GB
|   |
|   |   N°         label   FS      Size
|   |--sda5-----> OpenSUSE ext4     5 GB 
|   |--sda6-----> FreeBSD           5 GB
|
|   N°   type      label   FS      Size
|--sda4 primary     LVM    lvm   1536 GB
    |
    |    N°       LV name  FS      Size    Mount point
    |----1         home    ext4  1300 GB     /home      
    |--- 2         ubuntu  ext4    25 GB     /    
    |--- 3         debian  ext4    10 GB     /
    |----4         fedora  ext4    10 GB     /
    |----5         mint    ext4    10 GB     /

Notes:

1. GRUB2 has its own partition, that will be updated from inside Ubuntu with the following command: grub-mkconfig –o /media/btldr/boot/
2. Each distribution will keep it's own native bootloader in it's own partition just in case. Anyway GRUB2 is going to do all the work. If there's a problem, I can chainload to the selected partition (I'm thinking of the distributions that are going to be inside sda3).
3. Unfortunately I won't be using GPT at all because it seems it is not completely supported yet by all distros, and I don't want to struggle so much as long as I can avoid it.
4. Home partition is going to be shared among all distributions using different user folders.
5. I'm very concerned about resizing partitions and the physical volume of LVM. I placed the "distros" partition (/dev/sda3) outside LVM because there are some distributions or systems such as FreeBSD that doesn't support it, or doesn't support it easily (example: OpenSUSE). I want to be able to free space from /dev/sda3 and resize the logical partition and give that extra, freed space to /dev/sda4 (the LVM physical volume) so I can extend the LVM volume group and therefore the logical volume home.
6. All sizes are approximate.

Questions

1. Will this procedure allow me to extend /dev/sda4 whenever I want?
2. Is it better to place the logical partition (distros) in sda4 (at the bottom of the disk) and the LVM partition before, in sda3? I guess not, that it is simpler to extend the LVM partition in the scheme I designed, but please correct me if I'm wrong.
3. What is the best way to create the logical volumes in LVM? I heard something about contiguous and non-contiguous logical volumes.
4. What is the best order of logical volumes I should follow or choose?

My idea is to extend the home partition if I need so. So I didn't give the whole capacity to LVM in the beginning because it is hard to shrink, so I'll be giving it more capacity, extending it gradually if I see I need it.

Any other ideas, advices or suggestions will be hugely appreciated too.

Thank you

PS: Sorry for possible mistakes, I hope I explained it all clearly.

TroN-0074 · 07-27-2012, 09:07 AM

10 GB is good but you have lot of room, why not 15GB or 20GB for each OS's root.
OpenSuse will benefit for having a larger root partition 5GB is really low, unless you are running it with out X.
FreeBSD is not going to work with 5GB partition. Unless you are not going to install anything from the Ports other wise I would suggest
For FreeBSD
swap 1G , BSD doesn't use swap until most of the memory is used
/ 1G to 8G depending on how much you use the root account
/var 512MB to 4GB depending on desktop and applications
/usr 8GB to 16GB , depending if you modify the kernel or update frequently.
/home 24GB or more of the disk space avaiable. This is where all the user accounts get created, and where you do your work.

The compiler in FreeBSD uses /usr as the working directory so you need to give it some room
By default home is created under /usr in FreeBSD but you can modify it to mount like /home

One suggestion is to use different graphical interfaces in each distro as I was told the system can give you some errors if you have the same version of files in each partition (I dont know how accurate that is)
Another thing have different user IDs in each distro like Jonh in one then Jonh1, Jonh2, Jonh3... in the others so you wont mess up permissions in each distro.
And it might be a good idea to have each root partition formated in different file systems, ext3, ext4, btrfs, ZFS (FreeBSD), ReiserFS, XFS. Format the /home partition only once perhaps use ext3 for it and then set up the installer to allocate a mount point to it each time you do a new installation.

Good luck to you.