This is a pre-purchase question - I have no knowledge of unRAID and attempted to do a search but didn't know enough of the terminology to ask the right questions it seems.

 

I'm wondering about using a SilverStone DS380 Black NAS Case as follows to build a new NAS using Unraid OS as follows (using only the hot swappable 3.5" bays):

 

Bays 1-4 Raid Array, at this stage 4x2TB I already own.

Bays 5-6 add to the array in the future, this will require me to add a PCIe card with an extra 2 SATA ports as the planned motherboard only has 6 SATA ports.

Bay 7 unassigned drive but visible as a drive over the network (say 4TB at this stage as my old NAS only has 3TB of data on it at present)

Bay 8 future unassigned drive but visible as a drive over the network

 

The purpose is to back up the raid array to the unassigned drive as a mirror of the array. The end user should only see 2 disks; "data" and "backup".

 

The purpose is to avoid the backup drive being external, it is to be a mirror of the RAID so that we don't grind to a halt while the array is rebuilt in the event of a disk failure (these two decisions are for reasons that make sense to us but may be illogical to others, so don't try to convince me otherwise ).

 

So, three questions before I leap into unRAID:

- Can what I want be done?

- If so, how, how easy is it to do (ok, so that's 2 really but these two are related).

- If I have a non-HD catastrophic failure can I mount my 4 drives in a Ubuntu box and see the directory tree as displayed in it would be in the share (just in case backup disk is corrupted by said failure) to aid in data recovery?

 

Thanks for reading to the end of my first post and thanks in advance for your replies.

 

Edited September 14, 20178 yr by Bomber

Hello and welcome.

 

First, a standard disclaimer - unRAID isn't RAID.  So when you say that you want to have bays 1-4 house the RAID array, I'll interpret that to be "that's where I want to put the data and parity drives which comprise the unRAID storage array".  It's always worth saying that out loud to set expectations... unRAID will allow you to add additional disks into the storage array at any time, regardless of which bay they are housed in.

 

The Unassigned Devices plugin, which you'd obtain using the Community Applications plugin, will allow you to mount and share disks outside the unRAID array.  As to what users can see, you manage that via Sharing.  You can share out unassigned devices, and both array disks (not preferred) and user shares (preferred) are how you share out the array.  A user share is essentially a top level folder in the directory tree.

 

Regarding your backup strategy, a couple of thoughts.  First, unRAID will emulate a failed disk - things slow down but they don't grind to a halt.  Second, you can sync your data to another drive but that isn't a thorough backup strategy.  Backups involve having offline data and potentially versioned data, which a simple sync doesn't accommodate.  In the event of a catastrophic failure unRAID disks are in a standard XFS format and would be mountable in Ubuntu, with exactly what you'd expect for the directory tree.