On Premise: Issue with GRUB when 3CX Debian on RAID

[sven2]

Hello,
We are having issues installing 3CX on a new system where we can have all disks in RAID1. This would provide protection against disk failure. The article on high availability also suggests running on RAID.
The problem concretely is the following. When installing 3CX, in the Debian installer the grub-installer script always fails. My guess is that somehow /dev/sda is hard-coded in the grub-installer script and it does not work when installing on other disks (the disk name when using RAID is something like /dev/mdXX).
We have tried doing a pure Linux software RAID with the multidisk driver, but it did not work. The server we are using (DELL PowerEdge R240 with S140 software RAID controller) has software RAID features, but with this configuration it did not work either.
On the same server, when installing on one disk (/dev/sda), the installation worked.

We also tried the stock Debian 9 installer (not the 3CX iso) and it did install successfully on a RAID disk.
Any pointers on how to get 3CX to run on a RAID?

Kind Regards,
sven2

 

[cobaltit]

Have you tried real (hardware) raid? Software raid, as you noted, is not supported

 

[sven2]

Hello cobaltit,
After a lot of trying out, I have found the following solution:
Using a Raid for the root and swap partitions and installing the EFI on a single disk (see below). One then copies the data from the EFI partition to the other disk and then one has a workable software RAID. This setup works out of the box, one just has to copy the files manually and register the new boot partition with the efi-BIOS. In our case the server recognized it automatically.
The one drawback of this method is that one has to copy the files in the efi partition after every update.
disk 1 | disk 2 ---------------------- | ESP | ESP | ---------------------- | RAID: root | ---------------------- | RAID: Swap | ----------------------

And regarding the software RAID of the PowerEdge R240, this works too, one just has to install grub-efi manually. The software RAID of the BIOS is only used during the boot process, after booting the RAID is managed by the linux kernel module md. We decided not to go with this solution, because it was much more work in case of a reinstallation.

Regards,
sven2