Hd pool/raid creation doubts for home NAS

Hi and thanks for reading this!

I find Rockstor impressive and more than suitable for my needs. Let me sum them up:

  • I keep a copy of my precious pictures on two dedicated 2TB HD, each of one being a sync’ed copy of the other with the help of “luckyBackup” Linux software (veteran Gentoo Linux user here).
  • I’m running out of space quickly and probably next spring I’ll have to add more storing space, so I decided to try Rockstar to not only upgrade my storage but gain NAS capabilities.

Since I’m on a tight budget, could I do this?

  1. Use my existing two 2TB drives to create a 4TB pool (pool A) with Rockstor.
  2. Buy a new 4 TB SSD drive and use it for pool B.
  3. Create a RAID 1 with pool A (two 2TB drives) and pool B (one 4TB drive).

Is that possible at all or have I misunderstood the pool and raid concepts?
Would there be a better option to take advantage of the two 2TB drives I already have?

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@urcindalo welcome to the Rockstor community!
There are probably many differing opinions out there, especially what a “tight” budget means :slight_smile:

Here is my take, but don’t take that as the end-all-be-all. Fundamentally, since these are your precious pictures, I am not sure whether you have other backup methods external to your current setup, or is your current 2TB drive 1 the “operating” drive, and you use the second 2TB drive as a backup that you store separate from your working system (since, if your system goes up in flames you would still lose both drives).
I will make some other assumptions as part of my opinion:

  • you will already have some type of smallish SSD drive available to run the Rockstor OS on.

Instead of buying a 4TB SSD, you could purchase 2 x 4TB HDDs probably for the same total amount of money (e.g., a 4TB WD Red for USD79 each vs. USD140-250 for a single 4TB SSD in the U.S., your mileage may vary in a different part of the world, of course).

You could then:

  1. put the 2x 2TB and 1x4TB into your Rockstor box
  2. create Pool A from those 3 drives
  3. set up a btrfs RAID1 on the pool, which should give you 4TB storage with some redundancy
  4. Use the second 4TB in an external case, or in a physically separate system dedicated to backups and set up your luckyBackup software (or rsync, or what have you) to periodically back up your pictures onto the HDD external to your daily usage Rockstor system.
    That way you essentially have 3 copies floating around for your pictures, which should make it reasonably save. And you have “size parity” between your Rockstor storage available and your backup drive. Of course, if you can set up the second 4TB drive as an external backup drive that you can store off-site to further minimize the risk and a good backup schedule … you get the picture.

One thing I would ensure is that it’s worth to continue to rely on those 2TB drives. The S.M.A.R.T. statistics will give you some indication, though not foolproof. Of course, depending on how “old” these are, there will also be a difference in read-write speed compared to the newest incarnation of drives. Good part is, you can start with a setup like this, when your budget improves down the road, you could start adding another 4TB drive, further increasing your storage, and/or replacing the 2TB drives. But I would ensure, that as your Rockstor capacity grows, your backup capacity does likewise. For example:
in 2 years buy a 6TB drive, move the backup 4TB to your existing pool (gain 6TB Rockstor storage space) and use the 6TB as your new backup drive …

As usual, in these case, the answer is really “it depends”, but the one thing I will emphasize is that Rockstor by itself is not a backup solution, so, especially for your pictures, a corresponding backup setup is almost equally important.

Hope, that gives you some further ideas.


Thanks very much for your help. Your ideas are very useful.

What I meant by “tight” budget is I want to achieve my goal the cheapest possible way, without expending more than necessary. For instance, I could go with a Synology DISKSTATION but I’d rather expend on HD than on $$$ cases.

My current setup (2x 2TB HD) consists of an internal 3,5" drive inside my working box and an external ADATA HD710 Pro (MIL-STD-810G grade). I also backup to my Amazon Prime account.
As per your suggestion, I will probably get a 4TB ADATA HD710 Pro drive as the new “portable” drive and leave the other ones attached to the NAS.

Since my new and dedicated setup will probably rest on my living room (next to my router’s ethernet ports) I want it to be as silent and small as possible. So, I’m thinkg of a Raspberry Pi4 as the NAS box but I would need some kind of docking station to connect the drives. Any suggestions or ideas?

I know Rockstor is not a backup solution, hence the building of a NAS: I want my pictures out of my working box, to be able to access them from anywhere and to take advantage of pool/raid capabilities with easy grow/upgrade posibilities as a bonus.

My current drives are only mounted and used to backup new pictures or process them, so most of the time they are iddle. I don’t think they are that exhausted but, anyway, I could go without them in the NAS and use them for other purposes. However, since I don’t currently forseee any other use for them, I’d like them to be a part of the NAS pool.

Any suggestion, even a totally different approach to my goal, is more than welcome.

You could look into something like the Argon EON, which has passive cooling, is specifically for Pi and has 4 drive bays integrated … currently around 150USD (but you will need to supply the Pi). That way you would have the case that holds everything …

but that might break your plan for the “least expensive” possible. If you were to use some sort of USB hub, search the forum, there are a few threads around unique serial numbers for the drives not being passed through, confusing the btrfs setup, etc. I have no experience with that, but I assume if you were to get a SATA card like the IO Crest, then that might not be a problem, but the Rockstor installer might not have the corresponding kernel drivers for that, so there is that.

But, we do have peeps on the forum that have successfully built Rockstor on a Raspberry Pi (I think @xztd34 you were one of them, right?) that have likely more practical advice.