On 1/11/23 02:09, Simon Matter wrote:
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.
.... trimming
- 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?
What I usually do is this: "cut" the large disk into several pieces of equal size and create individual RAID1 arrays. Then add them as LVM PVs to one large VG. The advantage is that with one error on one disk, you wont lose redundancy on the whole RAID mirror but only on a partial segment. You can even lose another segment with an error on the other disk and still have redundancy if the error is in another part.
That said, it's a bit more work to setup but has helped me several times in the decades ago.
Ah, now I begin to get it. Separate partitions RAIDed.
Yes, exactly, sorry for not being clear enough. The structure of disk 0 looks like this:
$ lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT /dev/nvme0n1 NAME FSTYPE SIZE MOUNTPOINT nvme0n1 745.2G ├─nvme0n1p1 vfat 200M /boot/efi ├─nvme0n1p2 linux_raid_member 1G │ └─md0 xfs 1023M /boot ├─nvme0n1p3 linux_raid_member 186G │ └─md1 LVM2_member 185.9G │ ├─main-root xfs 30G / │ ├─main-swap swap 16G [SWAP] │ ├─main-tmp xfs 10G /tmp │ ├─main-var xfs 200G /var │ └─main-imap xfs 1.2T /var/spool/imap ├─nvme0n1p4 linux_raid_member 186G │ └─md2 LVM2_member 185.9G │ └─main-imap xfs 1.2T /var/spool/imap ├─nvme0n1p5 linux_raid_member 186G │ └─md3 LVM2_member 185.9G │ └─main-imap xfs 1.2T /var/spool/imap ├─nvme0n1p6 linux_raid_member 186G │ └─md4 LVM2_member 185.9G │ ├─main-var xfs 200G /var │ └─main-imap xfs 1.2T /var/spool/imap └─nvme0n1p7 15.8M
Regards, Simon