Distro Installation to Second HDD while preserving current working installation?

Hi All,
I have box with a working elastix installation on it. This system is in production use.

I want to move to the FreePBX latest Distro (Centos 6.4)

But I want to have the opportunity to ‘back out’ if my installation goes wrong. I use a hardware Sangoma A101 card to connect to my ISDN, so I need to use the same box, rather than install to a completely different machine then make the switch.

My idea was to utilise the second drive on my system to install the distro, and then, all going well, make this second drive my primary boot drive. I could then switch between the two installations just by changing my primary boot drive, and rebooting.

I have downloaded the distro boot image, but I am afraid that it is not going to ask me what drive to install to, and will overwrite my current installation.

Is there something I can do to ensure I install to my second drive and not overwrite my current installation?

A bit more info about my setup:
There are two logical drives on my system, both created by a hardware raid controller. There are 4 actual HDDs on the system, Drive 0 and 1 used to make a Raid 1 logical drive, and Drive 2 & 3 used to make the second logical Drive, Also Raid 1.

Any suggestions appreciated. Thanks in advance.

Remove the drive from the computer. YOu would have to manually setup Grub to do this and if you have to ask I assume you are not familiar.

Since every disk controller and system is different it would not be possible to give you instructions.

Lastly, even support can’t help you with this because unless you have a machine with a remote management console you can’t do support on install process.

If I were you I would purchase a drive bay for the computer. Many of the newer ones are caddie less.

My first thought was to remove the drive from my computer, but, as they are a raid logical volume, I would need to remove both of them. If I boot without the two hdds present, my Raid controller will detect their removal, and I suspect that if I put them back in later, the Raid Controller will just re-format them.

I am not sure how adding a drive bay will help?

You are correct, I am not familiar with GRUB beyond its basic function - but I am a quick learner :slight_smile: . Are you saying that I should use GRUB to set up a dual boot system ? Does this mean I would need to separately install Centos as the dual boot OS, rather than us use the distro installer? I could then convert to FreePBX using the instructions I have seen on this site for converting a stock install.

You controller would see the drives. It writes the RAID info to the boot sector.

What type of RAID controller? Does it have the option to select boot device?

The external bay would have allowed you to easily swap out the drives.

And yes to your question of manual install, or you could pull the RAID’s, install to the new disk, reinstall the RAID, set the RAID as the default boot volume then modify the grub.conf that the distro installs to add a menu selection t boot the new distro.

I can select the boot drive- in the BIOS I can nominate either logical drive (0 or 1) as my boot drive.
Is this enough? This was my original question.
If I change the boot drive to my second logical volume (presently empty) and then boot to the Distro ISO and run the default install, will it install to the second logical drive (logical volume 1) because it is the boot drive ? Would it (the distro installer) leave the non-boot drive (logical volume 0) alone ?

If so, this would be my simple solution. I can just switch the boot drive in bios, and have a dual boot system without making any changes to GRUB ?

What I am scared of is that the distro install will also affect my non-boot drive in some way, so that if I try to revert to it, it will not boot anymore.

I would not risk that, the distro does not look at the BIOS so you would have to select custom install and make sure you pick the right drive.

That’s why I advised against it. Too big a chance to make a mistake.

Thanks for your all your assistance. Now I know I was right to be afraid!

I think I will image the drive first, before I do anything. Then it seems like my best bet is to attempt to set up a dual boot using GRUB.

Or, after having imaged the drive, I may just go with your first suggestion, and remove the drives I don’t want touched. If I can’t get them to come back after I put them back in, I can restore from the image…

After I summon up the courage to do this, I will report back about how I went.
(This is why I prefer working with virtual machines.) Can anyone sell me a virtual A101 ?! :wink:

Virtual 101 on what platform ???

CentOS includes Kernel Virtual Machine support. It is so easy to spin up a VPN with libvirt.

Install a bare bones CentOS for the OS then the distro as a VM.

You may also want to look at Proxmox. It server us well for years before we had to go to a clustering platform.