How To Set-up A Secondary Disaster Recovery Installation?

[ahriman]

When I ordered my server, aside from the primary RAID volume, I had them include a SATADOM disk. The idea was to have a spare Proxmox installed there for recovery purposes if something were to ever happen to my drives or raid controller, so I could at least boot up the server and start the more critical VMs from the SATADOM.

For the life of me, I can’t get the server to boot into the other Proxmox install on the SATADOM. The BIOS gives me the option to boot to either device at start-up, but no mater what I select in bios the server always boots to the copy of Proxmox installed on the SSDs.

I’m now thinking perhaps the installation on the SATADOM was damaged somehow after Proxmox was installed to the RAID volume and that’s why the BIOS won’t boot it. My vendor installed Proxmox first to the SATADOM and then they installed again to the RAID. Is it possible they damaged it somehow when installing a second time? They’re telling me the issue is with Proxmox’s Grub bootloader configuration, that this is some kind of Proxmox configuration issue. That doesn’t seem right, but I have no way to verify this.

When I run sfdisk from the primary Proxmox install I can see both Proxmox installs on /dev/sda and /dev/sdc and it looks like all the boot partitions were created correctly on each volume. Does anyone have any ideas to orient me about how to explore this further?

root:~# sfdisk -l

Disk /dev/sdb: 2.91 TiB, 3199482200064 bytes, 6248988672 sectors
Disk model: PERC H730P Mini
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/sda: 372 GiB, 399431958528 bytes, 780140544 sectors
Disk model: PERC H730P Mini
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 9A5A41F7-FF1A-4EAF-B69C-25236C4B6ABF

Device       Start       End   Sectors   Size Type
/dev/sda1       34      2047      2014  1007K BIOS boot
/dev/sda2     2048   1050623   1048576   512M EFI System
/dev/sda3  1050624 780140510 779089887 371.5G Linux LVM

Partition 1 does not start on physical sector boundary.


Disk /dev/mapper/pve-swap: 8 GiB, 8589934592 bytes, 16777216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/pve-root: 92.75 GiB, 99589554176 bytes, 194510848 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/sdc: 14.47 GiB, 15533604864 bytes, 30339072 sectors
Disk model: USB DISK 3.0   
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x13f7e9b8

Device     Boot Start      End  Sectors  Size Id Type
/dev/sdc1  *     2048 30339071 30337024 14.5G  c W95 FAT32 (LBA)


Disk /dev/sdd: 59.63 GiB, 64023257088 bytes, 125045424 sectors
Disk model: SATADOM-SL 3IE3
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 09B0A5FE-2241-44E3-8E5C-39A8D0B32DE3

Device       Start       End   Sectors  Size Type
/dev/sdd1       34      2047      2014 1007K BIOS boot
/dev/sdd2     2048   1050623   1048576  512M EFI System
/dev/sdd3  1050624 125045390 123994767 59.1G Linux LVM


Disk /dev/mapper/pve--OLD--F49781E2-swap: 7.38 GiB, 7918845952 bytes, 15466496 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/pve--OLD--F49781E2-root: 14.75 GiB, 15837691904 bytes, 30932992 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

 

[ahriman]

Hi, I just wanted to post an update. I have Proxmox booting from both the SATADOM and the SSDs, but there are conflicts with the volume names.
The main issue now is both installations are using the same lvm volume names and are all mixing together. I'm thinking there may be no way to actually get this to work.

Has anyone ever got a secondary backup/recovery install of Proxmox to work on the same machine? Or should I abandon this project? I really wanted to be able to boot into an alternate install of Proxmox if there was some kind of issue with my disks, but perhaps there's no way to actually make this work.

 

[Dunuin]

Backing up the system disk using clonezilla would be an alternative. Then you could boot into clonezilla and restore a working backup from an image.

 

[ahriman]

Thanks for the suggestion Dunuin. I may have to end up doing something like this. It seems Proxmox really just never contemplated that people might want to have a backup installation on the same machine.

The problem I'm seeing is that is no matter what install of Proxmox boots up it can still see the logical volumes on the other install.
I was thinking of renaming them like this:
https://www.thegeekdiary.com/centos...nd-mount-2-volume-groups-with-same-names/amp/
and then updating /etc/fstab

The problem is that Proxmox is all automated and names everything the same name. So both installs got /dev/pve/root /dev/pve/swap and /dev/pve/data
pve is the volume group name

However, it seems like Proxmox used mounting via path names in /etc/fstab instead of by uuid like they should have (why would they do this?). If I was to rename one of the volume groups with the uuid from the guide and then update that installs /etc/fstab I think it will work, but I'd really prefer to do this on the non-booting install. I want to keep the standard install plain vanilla for compatibility with updates, etc. If I do the volume changes on the non-booting volume its going to have a problem when I try to boot it.

 

[Dunuin]

I want to keep the standard install plain vanilla for compatibility with updates, etc. If I do the volume changes on the non-booting volume its going to have a problem when I try to boot it.

Without vanilla you could install a debian bullseye and then install the PVE packages ontop. That way you could name the VGs, LVs and so on as you like: https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_11_Bullseye