amnm wrote:Where can I find more information about this?
I'm not aware of any officiall documentation of the design but
schumaku have explained it here in the forum.
I have a four bay NAS with two hard drives installed. Which RAID is being used, Raid 0 or Raid 1?
RAID 1 for the system partitions.
Will that change if I install a third hard drive?
No.
Also if I decide to remove hard drive 2 will that have any implication on accessing my full data on drive 1?
It shouldn't, at least not if you are careful and remove all shares created on drive 2 and any other existing dependencies to it.
Of course removing disk 2 would at the same time remove the disk redundancy for your system partitions, thus making the system totally vulnerable to a disk failure and at the same time make your 4-bay NAS effectively a single bay unit.
Personally I doubt you gain any stability by removing a disk, you only make the NAS less useful. When disks start failing, your single disk configuration will give you all sorts of problems anyway. I would make sure external backups of all data are in place and be happy as long as the current configuration works.
In the future, buy Qnap approved disks and consider using a fault tolerant RAID-configuration (RAID 1, 5, 6 or 10).
RAID have never ever been a replacement for backups. Without backups on a different system (preferably placed at another site), you will eventually lose data!
A non-RAID configuration (including RAID 0, which isn't really RAID) with a backup on a separate media protects your data far better than any RAID-volume without backup.
All data storage consists of both the primary storage and the backups. It's your money and your data, spend the storage budget wisely or pay with your data!