On 7/11/23 13:18, Mick Ab wrote:
I am thinking of changing my storage from two 1TB hard drives in a software RAID 1 configuration to two M.2 Nvme 1 TB SSDs. The two SSDs would be put into a software RAID 1 configuration. Currently each hard drive contains both the operating system and user data. What steps would you recommend to achieve the above result and would those steps be the quickest way ? One of the M.2 slots can operate at PCIe 4.0 and PCIe 3.0, while the other slot can only operate at PCIe 3.0. If they are to be in a RAID 1 array, I guess that both slots should be operated at PCIe 3.0 speed.
I would backup the system configuration files and data, power down, remove the HDD's, install the NVMe drives, boot Debian installation media, do a fresh install, restore/ merge the system configuration files, and restore the data.
The above should be the most reliable approach and produce a "known good" Debian system instance.
AIUI Linux md RAID can deal with block device speed differences.Taking a step back, you might want to re-think using two 1 TB devices in RAID1 for everything -- boot, swap, root, and data. I put boot, swap, and root on a single 2.5" SATA SSD's and keep the entire instance small enough to fit onto a "16 GB" device (you might want to target "32 GB", "64 GB", etc., if you install a lot of software). I then put 2.5" SATA trayless bays in all of my computers. This makes it easy to move OS instances to other machines (subject to BIOS/UEFI compatibility), to clone images to additional devices (USB flash drives, HDD's, SD cards), and to take and store images on a regular basis for disaster preparedness/ recovery. I would then wipe the 1 TB HDD's and build a ZFS pool using the HDD's as a mirror. A surplus of memory will help ZFS performance. For further ZFS improvements, add small/ fast/ high endurance NVMe devices as ZFS cache and/or log devices.
David