MergerFS & Snapraid

This page is all about the specific deployment configuration of using MergerFS and Snapaid in tandem. Which can also be seen as a free alternative to Unraid.

 Replacing a parity disk

First format the disk as required (see also basic).

Then add the new disk as an extra parity disk. Which might look something like this (/etc/snapraid.conf):

data d1 /mnt/disk1
data d2 /mnt/disk2
data d3 /mnt/disk3
parity /mnt/parity1/snapraid.parity
2-parity /mnt/parity2/snapraid.parity-2 # <-- this being the new disk

Afterwards do a full parity sync by providing -F to snapraid sync, as follows:

sudo snapraid -F sync

Next up remove the old parity disk from the config, and add it as a data drive, make sure to remove the parity file from it. Make sure to number the new one correctly.

data d1 /mnt/disk1
data d2 /mnt/disk2
data d3 /mnt/disk3
data d4 /mnt/parity1 # <-- old parity disk
parity /mnt/parity2/snapraid.parity-2 # <-- new parity disk

Of course, it might be smart to update the mountpoints accordingly. That was not done here for the sake of clarity.