Disaster recovery - creating external bootable disk

[etcetera]

RHEL 8 and I run LVM2.
My rhel root volume group is composed of 2 5-TB NVME SSDs. Stupid design, I know, I didn't configure this myself and have no choice in the matter. The root VG doesn't need 10TB. A second VG would have been better and easier to admin. As any one of the two SSDs failing brings the whole VG down.
The size of the rhel VG is 10TB.
I am thinking about disaster recovery, either user error wiping something out or one of the two SSDs failing. Basically what to do if it powers on but doesn't boot.

I want to clone the entire 10TB contraption to an external HDD which is 10TB and is bootable. I wouldn't be using it often, if ever, it's only if the server is turned on and it doesn't boot. Because in that circumstance there won't be any time for troubleshooting.
An external 10TB SSD would be even better but not sure about the price point of it. Given the unlikely chance of failure, I think HDD would do.

If I use Clonezilla, I wouldn't be cloning a disk, which is the simple case, but in this case the root volume group spans two disks, or SSDs. Last time I ran I didn't notice the option to clone a volume group.

Maybe this solution?

How to use LVM snapshots to restore Linux systems

It can be cumbersome to create and recreate lab or practice systems. Use LVM and a basic WebUI to quickly restore your Linux systems back to a golden image.

www.redhat.com

 

[jpnilson]

Not an expert on volume groups but my gut says if you could live with half the space I would remove one of the physical volumes. May be more than what you want to do but you will be hanging out for a while until you acquire a backup. If restoration time is critical perhaps you need a warm backup ready to go.

 

[etcetera]

I cannot remove one of the PVs from the root VG because that would destroy the VG, it's very risky and complicated to shrink the root volume group. The system is working, I will probably end up breaking it. Then I need the space in it, due to the stupid design.
/, /var, /usr, etc. are OK with about 2TB while everything else should have gone to the other disk.

 

[f33dm3bits]

If I use Clonezilla, I wouldn't be cloning a disk, which is the simple case, but in this case the root volume group spans two disks, or SSDs. Last time I ran I didn't notice the option to clone a volume group.

What you could try is to use pvmove. Make sure all the current lvm volumes are not in use so you will probably be wanted to be booted in a rescue environment, then plugin your 10T disk. Then you can use pvmove on both of your ssd's to your 10T external hd, you would probably need to first create two partitions on your external hard drive to do that so that you can tell pvmove to which partition you want to each of the existing physical volumes. Just know I haven't done this but it sounds possible, if I were to do it I would test it out on a vm first. However the easier option and safer option would probably be to backup all your current data and configurations to the external hard drive and then reinstall your system with the disk and partition setup you actually wanted to use for your ssd's.