[Discuss] Fun with Synology (was WD My Cloud PR4100)

[Richard Pieri]

So. I've grown accustomed to having a bunch of little things on the HP
N40L with Debian which aren't available on the Synology DS.

So I installed Debian stretch. In a chroot directory. It's been working
well. Some of the low level kernel stuff is a little wonky because
Synology currently ships a 3.10 kernel and Debian 9 ships 4.9 kernels.
And by "wonky" I mean that Btrfs raid1 data doesn't divide capacity by 2
so 15TB raw shows up as 15TB rather than 7.5TB (that changed somewhere
in the version 4 kernels)

Wait... Btrfs raid1? Yeah, it wasn't hard. Synology uses a 2GB and a
2.5GB partition on each drive for it's internal use (I think) and the
rest for MD-RAID. I broke up the RAID6 volume, created a new single-disk
volume (/volume1) for the system drive, copied a deboostrap install from
the N40L over to /volume1. Chroot there, installed the btrfs tools
package and created a new Btrfs volume using the four unused data
partitions.

So I get the high-level DSM for the simple stuff and a full (enough)
Debian environment for the rest. Best of both worlds.

-- 
Rich P.