For about a year now I've been mulling over various computer upgrades - the first of these was buying the laptop just over a year ago. But that was only step one on the grand plan to upgrade all the things, and now the next steps have happened.
As with many things there was a particular trigger for it, and in this case it was my browser refusing to talk to Athena (a ReadyNAS Duo V1) because it only speaks TLS 1.0 and the browser makers have all decided that TLS 1.0 is completely broken and cannot be used anywhere. Nevermind that this is a local network and the NAS admin page is not exposed to the internet...
Anyway given that Athena was a decade old, it was long overdue an upgrade to something a bit faster. And after much pondering, I settled on a shiny new Synology DS920+! It slots neatly into the shelves that make up the comms tower in this flat and is a fair bit beefier - it's got a quad-core 2.7GHz Celeron J4125 with 4GB RAM, against the single-core Sparc chip and 256MB RAM in the old unit. This will help with other plans to turn it into more than just a NAS.
Setting it up was straightforward: power it up, feed it a drive (a spare 3TB one that used to live in Nyx), wait a bit while it installs DiskStation Manager, and then start configuring! The Synology software is a lot more capable than the ReadyNAS RAIDiator firmware and I can see I'll have lots of fun getting it tweaked just how I want... but in the meantime, the immediate challenge was to migrate from Athena .
My end goal is to load out Caerus with 4x3TB drives, probably as a pair of RAID-1 arrays (RAID-5 is just asking for trouble these days once you get past a few TB per drive, and RAID-6 with only 4 bays doesn't have any benefit over RAID-1 or RAID-10). I do have the drives, but there's one small problem with it: three of them are currently in Nyx (the desktop) and won't be removed until that gets upgraded. So as a stop-gap I'll reuse the 2x2TB drives from Athena, but those have data I want on them and the ReadyNAS RAID format is different.
So, my cunning plan to migrate without losing redundancy is this:
1. Fit the initial 3TB drive in Caerus, and configure it as a single-drive SHR volume
2. Copy everything from Athena to Caerus
3. Move one 2TB drive from Athena to Caerus, and configure that as a second single-drive SHR volume
4. Within Caerus, copy everything from the 3TB volume to the 2TB volume.
5. Move the second 2TB drive (decommissioning Athena), and expand the second SHR volume onto it (which will turn it into a RAID-1 array)
Carrying that out was mostly straightforward, apart from step 2: I couldn't find any commands in DSM that would pull data from another location (there's plenty of backup options but they're all based around backing up this NAS to somewhere else, or working in combination with client software). So instead I created a backup job on Athena to push the entire volume across (over NFS, because I couldn't get the rsync connection to work) and left that to run overnight. Everything else went as expected, including Athena emailing me when I pulled the first disk (good to know that works!) and the copies within Caerus, and now I have 5TB of partly-redundant storage and a whole pile of addons to play with. I have plans for Caerus...