I have a pair of large nVME drives in my CentOS 8 Stream server, configured in mdadm raid 1.
I wish to install a pair of smaller (cheaper) nVME drives, move everything across, and then remove the larger drives.
df -h looks like:
Filesystem Size Used Avail Use% Mounted on
devtmpfs 63G 0 63G 0% /dev
tmpfs 63G 147M 63G 1% /dev/shm
tmpfs 63G 1.3M 63G 1% /run
tmpfs 13G 0 13G 0% /run/user/0
tmpfs 13G 0 13G 0% /run/user/1000
tmpfs 63G 0 63G 0% /sys/fs/cgroup
/dev/md1 990M 386M 537M 42% /boot
/dev/md2 9.8G 2.1G 7.2G 23% /home
/dev/md3 3.5T 598G 2.7T 18% /
fdisk -l looks like:
Disk /dev/nvme1n1: 3.5 TiB, 3840755982336 bytes, 7501476528 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 95B7BF67-6440-4C65-B971-E8165C9AEC0E
Device Start End Sectors Size Type
/dev/nvme1n1p1 4096 16781311 16777216 8G Linux RAID
/dev/nvme1n1p2 16781312 18878463 2097152 1G Linux RAID
/dev/nvme1n1p3 18878464 39849983 20971520 10G Linux RAID
/dev/nvme1n1p4 39849984 7501476494 7461626511 3.5T Linux RAID
/dev/nvme1n1p5 2048 4095 2048 1M BIOS boot
Partition table entries are not in disk order.
Disk /dev/nvme0n1: 3.5 TiB, 3840755982336 bytes, 7501476528 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 76BED273-6B1B-4966-A2DB-2F4252274B37
Device Start End Sectors Size Type
/dev/nvme0n1p1 4096 16781311 16777216 8G Linux RAID
/dev/nvme0n1p2 16781312 18878463 2097152 1G Linux RAID
/dev/nvme0n1p3 18878464 39849983 20971520 10G Linux RAID
/dev/nvme0n1p4 39849984 7501476494 7461626511 3.5T Linux RAID
/dev/nvme0n1p5 2048 4095 2048 1M BIOS boot
Partition table entries are not in disk order.
Disk /dev/md1: 1022 MiB, 1071644672 bytes, 2093056 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md2: 10 GiB, 10727981056 bytes, 20953088 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md0: 8 GiB, 8580497408 bytes, 16758784 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md3: 3.5 TiB, 3820217499648 bytes, 7461362304 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
This is a production machine, and I hope to do this without anything going wrong... My webhost has said they won't do the migration, I'm on my own.
I've never done anything like this, and don't know how plausible or risky it is - all guidance appreciated!
(I also have a pair of SATA drives in RAID 1, sda/sdb -> md4 which I've removed from the outputs above for simplicity. I assume they're irrelevant, but thought I should mention in case my assumption is wrong)
