Planning My HD Setup... Mirror vs. RAIDZ1 Config?

[r0b0ty]

Hello everyone.

I'm very new to FreeNAS (and to network storage in general), but I'm playing around with it in Virtualbox and reading the reference documents and posts. I have a question that I believe may be trivial for most of you.

I placed an order for THREE WD Red 4TB NAS Hard Disk Drives. In addition to them, I have a standalone Apple Time Capsule with around 1.3 TB of free space. Currently, I only have about 150 GB of data worth keeping on FreeNAS. This data is already backed up, both on an external drive and on the Time Capsule itself.

I've read that I will need to back up the data on FreeNAS, despite ZFS and any mirroring/RAID setup I employ... hence my question. Seems like I have the following two options:

1) Set up FreeNAS in a Mirror configuration, using the third drive as my backup drive?

OR

2) Set up FreeNAS in a RAIDZ1 configuration, using the Time Capsule as a backup drive?

Which would you recommend? Any other suggestions I have not thought of?

Frankly, I'm leaning towards option 2) as it would allow me to have more space from the get-go, and I don't see myself filling up the new drives very quickly (giving time to save up for more hard drive space). In the meantime, I have over 1 TB of free space on the Time Capsule.

Anyway, your feedback is greatly appreciated!

 

[8-bit Yoda]

Most people in this forum do not recommend to run a RAIDZ1 for drives > 1GB for your production (main) system.
You have a relatively small amount of data. I would stick with two drives in a mirror and return or cancel the 3rd drive.

 

[Stux]

I’d suggest the mirror and use the third drive as your backup.

 

[toadman]

For sure the mirror is the way to go given that it doesn't appear you space needs are all that great. In this case the mirror is better because...

(1) It will provide far more storage than you need for the foreseeable future (4TB vs 150GB), so space is not an issue even at 50% redundancy
(2) RAIDZ1 has two problems...
(a) It requires 3 drives, so you are paying for a drive you don't (apparently) need and
(b) RAIDZ1 is not recommended at those drive sizes due to rebuild time in the case of a failure and the possibility of a 2nd failure (which would destroy the pool) during a rebuild.

As for the backup, yes, either use the 3rd drive (which would match the size of the pool so you would have sufficient space as the pool grows beyond say the 1TB available on the time capsule) or one of your other drives depending on their space availability and age/reliability.

When you are ready to expand the pool, you can then just add two more drives in a 2nd mirror. Less expensive than adding 3 more drives in a 2nd RAIDZ1.

 

[r0b0ty]

I just wanted to thank you all for the prompt and sound recommendations. It's clear that a "Mirror + 3rd backup drive" configuration is the way to go. I have so much to learn, but I'm looking forward to it. As is always the case... the more you read, the more you realize you don't know a thing! ;)