I am trying to set up a software RAID on an existing AlmaLinux 9 LVM OS. Following instructions I found here (for Debian), I run into trouble when I get to the
mdadm --create command.
As per the instructions, I’ve copied the partition set up from the original to a blank drive, and made the new drive’s LVM Linux partitions “raid autodetect” using “fdisk /dev/sdh” command.
The next step is to create new degraded RAID arrays, using
mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdh1 for the two partitions (md0 and md1 for sdh1 and sbh2 respectively).
However, at this point, I get this:
mdadm: partition table exists on /dev/sdh1 mdadm: partition table exists on /dev/sdh1 but will be lost or meaningless after creating array mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 Continue creating array?
… at which point I answer no.
Here’s the lsblk for the disk with the live OS (sdb):
sdb 8:16 0 465.8G 0 disk ├─sdb1 8:17 0 1G 0 part /boot └─sdb2 8:18 0 464.8G 0 part ├─almalinux-root 253:0 0 70G 0 lvm / ├─almalinux-swap 253:1 0 4.4G 0 lvm [SWAP] └─almalinux-home 253:2 0 390.3G 0 lvm /home
I copied that to the sdh disk, so it had the same format when I was trying the above. I am leaving the sdh out of the lsblk response for now, because I had reformatted that disk as I was trying different things.
What should I do? Thanks for any help.