Re: Will this in-place conversion from LEGACY/MBR RAID1 boot to GPT/EFI boot work
On 10/6/25 18:13, Ram Ramesh wrote:
Hi,
I have an old machine that I installed with MBR/legacy BIOS/RAID1
So, RAID1 in the motherboard chipset? What motherboard? What chipset?
What Setup settings?
on two intel nvme 2TB SSDs.
Model numbers?
Luckily, RAID1 is on a partition and this the
whole SSD still has room for GPT conversion.
The secondary GPT partition table requires the last 34 sectors on the
disk. The partition information posted below indicates that those
sectors are already in use by /dev/nvme0n1p2. So, you will need to
shrink /dev/nvme0n1p2 before you can apply GPT partitioning to the disk.
Here is the MBR partition table (both SDDs are identical)
Disk /dev/nvme0n1: 1.86 TiB, 2048408248320 bytes, 4000797360 sectors
Device Boot Start End Sectors Size Id Type
/dev/nvme0n1p1 2048 67110911 67108864 32G 83 Linux
/dev/nvme0n1p2 67110912 4000797359 3933686448 1.8T 83 Linux
When you post console output, please post the prompts and the commands
issued. That is the correct way to do it.
RAID1 is on the second partition and first partition is free/empty.
RAID1 is further divided in to partitions
Please describe how RAID1 is divided into partitions. Please post a
console session that provides the details.
as part of debian install.
What Debian? Please run the following commands and post the console
session:
$ cat /etc/debian_version ; uname -a
I need to upgrade my hardware and legacy boot is not supported anymore
in most systems. So, need to convert to EFI boot. Since I have RAID1, I
want to try it in place. Here are the steps I planned.
1. Find the BIOS boot disk and do not touch it (let us assume this is
the the first SSD)
2. Fail and remove the second SSD in RAID1 and convert to GPT
1. Delete all existing partitions
2. Add EFI and BIOS boot partitions and the RAID1 partition of
identical size. Keep the unused blocks in a partition as before.
3. Add back the new GPT partition to RAID1 and wait for sync
4. Once RAID1 is ready, convert boot to EFI boot on the second drive
and reboot to check.
5. Once EFI boot is working, remove/fail *first* BIOS boot SSD from
RAID1 and convert to GPT and add back.
Is this a workable plan or am I missing anything?
Regards
Ramesh
Disk surgery is highly complex. I learned long ago that my time, money,
and effort are better invested in record keeping, version control,
backup, restore, archive, imaging, scripting, and spare parts. Such
have a lower learning curve and a longer lifetime.
If you are going to get a new motherboard, processor, and memory, I
suggest that you buy or build a complete computer. Install a dedicated
disk for the OS. Install additional disks for the data. Do a fresh
install of Debian on the new computer. Then migrate your services and
data from the old computer to the new computer one step at a time. If
you do not have a second keyboard, mouse, and monitor, you might want to
get a KVM switch. Backup before you start. Backup as you reach
milestones during the migration. Backup when you are done.
David
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