What I never really considered was what I would do should the chassis fail and I'm left with numerous drives running a 'proprietary' RAID type (X-RAID) and potentially no source for a replacement chassis other than eBay or CEX.
I assumed it would be a matter of plug drives in through a number of SATA > USB adapters and just dragging the files off once the OS magically picked up and decoded whatever X-RAID was.
Luckily, I never had to find out but a friend's house recently caught a lightning strike which took out his router and the ethernet port on his NV+ (the NAS took the lightning, not the friend). The drives looked to be safe in the NAS but with no way to access them - the only solution was to put them in something else and see what we could do.
The thought was to add all the drives to machine with plenty of SATA ports available (four for the drives from the NAS plus one for the OS and restoration drive) and see what happens, X-RAID seems to be pretty close to RAID-5 so I doubt Netgear / Infrant messed around with it so much as to make it unreadable by anything else.
Ubuntu 14.04 is my go to OS here - so I installed that on a spare drive (at this point the NAS drives were absolutely nowhere near this machine for fear of overwriting them accidentally).
When your'e happy it's installed and running, power down and add the old X-RAID drives in. Once connected, boot up again.
WARNING: Don't run DF once you've mounted your drives with Fuse. There appears to be a bug that causes the fuseext process to crash and consume 100% CPU time. The 'du' command is slow (like, really slow) but won't crash your system.
Next, we'll need to make sure we've got the FUSE module installed for Ext2 filesystems. First we'll cheat a little and go into a root shell.
(Warning: this will put you in to a root shell. Be very careful what you type outside of this list as you can cause serious damage to things).
Next install the Fuse Ext2 package.
apt-get install fuseext2
Then, load the fuse module.
Next, we'll scan our connected drives for LVM volumes with
Now we'll activate the volume we need
vgchange -ay c
(vgchange will search for all LVMs, '-ay c' will activate any volume named 'c' which is the name for the main volume on a ReadyNAS).
Make sure you have a mount point created to mount the reassembled volume in
mkdir -p /mnt/readynas
(just an example, call your directory whatever you like under /mnt/)
Then finally (fingers crossed here)
fuseext2 -o ro -o sync_read /dev/c/c /mnt/readynas
All being well, you're data will all be available under /mnt/readynas (or whatever you called it). You're free to copy it off to a non RAID drive, thumb drive or whatever you have to hand.