installing 2nd Centos into new, empty logical volume of existing LVM

deskt0plinux · 10-02-2012, 08:48 AM

I have a single physical disk of "500G" with a Centos 6.2 64-bit install taking up the full disk in an LVM as follows:

Code:

[centoslive@livecd ~]$ sudo pvscan
  PV /dev/sda2   VG vg_test   lvm2 [465.27 GiB / 259.42 GiB free]
  Total: 1 [465.27 GiB] / in use: 1 [465.27 GiB] / in no VG: 0 [0   ]

and

Code:

[centoslive@livecd ~]$ sudo lvscan
  ACTIVE            '/dev/vg_test/lv_root' [100.00 GiB] inherit
  ACTIVE            '/dev/vg_test/lv_swap' [5.84 GiB] inherit
  ACTIVE            '/dev/vg_test/lv_home' [100.00 GiB] inherit

Now after using this setup for 6 months, I find that Centos 6.3 32-bit is better suited for my needs - using certain specific 3rd party programs with certain older versions is imperative for work - but is unsupported for 64-bit platform.
I tried out compat-libs and ia32-libs and a couple other solutions - VMware/Vbox is very slow.
And I also discovered 6.3 has far better network card support (at least for hardware in my workplace) compared with 6.2.

So I have about 250 G of space available into which I can make upto 3 more side-by-side Centos installs in the future, if I use say 80G for each install. I can make upto 3 80G logical volumes.

But can I use one (or each) of them to install Centos 6.3 32-bit (or later versions) ?

Will the installer allow installing to a single logical volume?
Will the installer update GRUB entries to make the 2 OSes - Centos 6.2-64 & 6.3-32 available as menu options or do I need to do it manually?

Grub version is GNU GRUB 0.97

Thanks in advance.

Regards,
deskt0plinux

iamswift · 10-10-2012, 08:03 AM

Check if this link is helpful?
http://www.linuxquestions.org/questi...cal-volume-ma-

deskt0plinux · 10-12-2012, 02:18 AM

Firstly, thanks for your reply!

From reading that blog entry, I am surprised to find that a basic installation of Centos can be done without using the installer/liveCD ! I'll try that as soon as I get a chance to do so. This means that I dont have to wipe partitions every time in the future I want to add a new version! - if it works it will be a great help.

lievendp · 10-12-2012, 02:58 AM

I think that if you layout your disk it's very easy and even comfortable to use multiple os on the same system

in your case, I would have a boot partition (not on lvm) per OS of only about 250MB where each os could store it's kernels etc.
Then you can create another lvm root partition (/) for each OS where you install the systems.
Ideally you have one shared /home partition (lvm) which can be used by both systems to store your data on.

When installing the new OS, you can boot into livecd and use chroot or just the empty lvm-based partitions to install the new systems. But don't install grub again, you already have it from your first OS installation. You can just add entries for the newly installed os in the existing grub, allowing you to multiboot.

rgds.