Finding the requirements for my first FreeNAS box

[u6f6o]

Hi,

I'd like to explain my strategy on how to find the right requirements for my future home nas build. It's the first time I use freenas, thus I'd highly appreciate any feedback.

One of my core requirements is to build a NAS that is easily extendible in case my space expectations turn out to be wrong. As I read from documentation, one should find out the current requirement and plan how much space is needed in ~3 years.

The nas will be used for the following applications:

1. Main fotos store
2. Plex streaming, mostly for my dvd rips
3. Backup for my MacBook and PC
4. Document store (including tax documents etc.)

While 3. and 4. are relatively static, especially 1. has potential to grow very fast (e.g. new camera with high resolution etc.). Currently, I'd estimate that 1.5 - 2 TB should be enough, thus I thought about the following strategy.

As a starting point, I'd go with 3 x 6 TB disks and use it as a Mirror 3 pool, remaining with~4.7 TB of usable data space.

When I finally realize that most of the space gone, I'd do the following:

• In case fotos require more space
  • Add another 3 x 6TB disks as a new vdev to the existing pool
• In case plex rips takes over
  • Add another 2 x 6TB disks as a new Mirror 2 pool
  • Copy over plex stuff from the other pool (unless ratio of space used is too bad)
  • If rips are lost, I am not so sad, maybe even a stripe would do it

In order to extend once, I need 5 - 6 SATA ports. If I want to extend a second time, I'd like to have at least 3 SATA ports left, thus I should either go with a mainboard that has 8 or 10 SATA ports.

RAM-wise, I'd go with 32GB. I think there is no need to go with more in my case.

That's basically it. I'd be happy about any feedback, thoughts or notes if something makes no sense.

Thx in advance,
u6f6o

 

[danb35]

Why are you planning three-way mirrors? They're a perfectly valid configuration, but quite wasteful of capacity, as you're using three disks to get the capacity of one. If it's a matter of critical data, that should have a separate backup in any event.

 

[u6f6o]

Basically my plan is to go with a chassis that can have up to 8 disks, currently Fractal Node 804 is my favourite (will be located close to my working desk).

Having this limitation of 8 disks in mind, the Mirror3 option with a minimum of three disks requires one disk less compared to RAIDZ2 as I understand. Thus, I'd have five bays left for further expansion instead of four.

As I have data of different importance, I'd probably later on add another pool with different configuration (maybe RAIDZ1 or Mirror or even Stripe) and put data there which I can risk to be temporary unavailable/gone.

Furthermore I want to max out my vdevs with 6TB disks (at least for the initial configuration, maybe I would need less later on) and another 6TB WD Red is not that cheap :)

Don't know if for my purpose better performance of Mirror brings much though!?

Anyways, I start to learn and love freenas/zfs - if you think this makes no sense, please tell me!

PS: My current idea for the build can be found here.

 

[u6f6o]

I thought about my configuration again. Actually, going with a RAIDZ2 variant with 4 x 4 TB disks, saves me some bucks, and I'd have 5.728 TiB available with this configuration.

In case space becomes a problem, I could replace the disks by 6TB disks one by one and enlarge the capacity of the existing pool. The remaining 4 x 4 disks I could use for the remaining 4 bays.

Actually I start to prefer this configuration. I read through quite a lot of configurations that use plex etc. with RAIDZ2, thus performance should be sufficient I guess!?

 

[danb35]

In case space becomes a problem, I could replace the disks by 6TB disks one by one and enlarge the capacity of the existing pool. The remaining 4 x 4 disks I could use for the remaining 4 bays.

...or you could just expand the pool by adding a second vdev of 4 x 6 TB disks in RAIDZ2.

I read through quite a lot of configurations that use plex etc. with RAIDZ2, thus performance should be sufficient I guess!?

RAIDZ2 is entirely adequate for Plex.

 

[u6f6o]

...or you could just expand the pool by adding a second vdev of 4 x 6 TB disks in RAIDZ2.

4 x 6 TB exceeds my budget. Most likely I'll start with 4 x 4 TB.

 

[danb35]

Fine, start with 4 x 4 TB. But you have an 8-bay server. When it comes time to expand the pool, one way to do it, as you suggested, is to replace each of the four drives, one at a time, with larger drives, resilvering after each replacement. Another way to do it is to add four new drives (in the four remaining bays), and add them to the pool as another RAIDZ2 vdev.

 

[u6f6o]

Thx for the input, it brought me to the final conclusion, that RAIDZ2 with 4 drives will be the better option for me.

Anyways, I hope my initial configuration will last for quite some time (currently I have low space requirements). When time comes to exceed the capacity, I'll decide based on the area that ate up most space. In case the not-so-important data grew most, I might consider a stripe or RAIDZ1 option for the remaining bays, otherwise I would go with RAIDZ2 again. Time will show