[CentOS] Upgrading system from non-RAID to RAID1

Wed Jan 11 01:57:32 UTC 2023
H <agents at meddatainc.com>

I plan to upgrade an existing C7 computer which currently has one 256 GB SSD to use mdadmin software RAID1 after adding two 4 TB M2. SSDs, the rest of the system remaining the same. The system also has one additional internal and one external harddisk but these should not be touched. The system will continue to run C7.

If I remember correctly, the existing SSD does not use a M2. slot so they should be available for the new 4GB SSDs while the old SSD remains in place. If I read the output from gparted correctly, this existing SSD is partitioned as follows:

- EFI system partition 260 MB and mounted as /boot/efi (formatted as FAT32).

- boot partition 1 GB and mounted as /boot (formatted as xfs).

- /root, swap and /home seem to coexist on a LUKS encrypted partitition using LVM2 PV.

My current plan is to:

- Use clonezilla to make individual backups of all partitions above.

- Install the two M2. SSDs.

- Use an external disk tool to partition the two new M2. SSDs as follows:

-- Create a RAID1 partition for /boot - same size as current, ie 260 MB

-- Create a RAID1 partition for /boot/efi - same size as current, ie 1 GB

-- Create a RAID1 partition for LVM2 and LUKS - the rest of the 4 TB SSD


- I do not see any benefit to breaking up the LVM2/LUKS partition containing /root, /swap and /home into more than one RAID1 partition or am I wrong? If the SSD fails, the entire SSD would fail and break the system, hence I might as well keep it as one single RAID1 partition, or?

- Is the next step after the RAID1 partitioning above then to do a minimal install of C7 followed by using clonezilla to restoring the LVM2/LUKS partition??

- Any advice on using clonezilla? Or the external partitioning tool?

 - Finally, since these new SSDs are huge, perhaps I should take the opportunity to increase the space for both /root and /swap?

- /root is 50 GB - should I increase it to eg 100 GB?

- The system currently has 32 GB of memory but I will likely upgrade it to 64 GB (or even 128 GB), perhaps I should at this time already increase the /swap space to 64 GB/128 GB?

Looking forward to advice and suggestions!