HDD & RAID questions

[Mr. S.]

I am brand new to NAS and I have been doing a lot of research into how to best setup my system.

I want to move all my data from my external drives and pc's over to the NAS and also keep a copy of all the data should I lose a drive.

I want to start small right now and be able to expand my drives in the future. For now I want to go with 2x 3TB WB Reds. The MB I plan on using will support up to 8 so I plan on adding up to 6 more in the future.

The first question is what type of RAID I should setup. Do I go with RAID1 or RAID10? Secondly, how do I go about adding additional HDDs to the NAS once it is up and running? I have been looking online for a tutorial on how to do this and I am coming up empty.

 

[Bidule0hm]

I recommend to read Cyberjock's ZFS guide (link is in my signature) that should answer your questions ;)

 

[Mr. S.]

Thank you for the info. It was helpful.

It looks like the safest option is RAIDZ2 since I could lose 2 drives and still have my data. I assume for that I need 3+2 HDDs. I assume that if I wanted to add more drives later on I would need to create a new volume and to be at the safest level, I would need to add an additional 3+2. This would allow me to lose 2 drives from Volume 1 and 2 from Volume 2 (4 total) and still have my data.

Is this correct?

Second question. What about just doing a RAID1 mirror with two drives and then building a second NAS also with two drives. Then having NAS1 backup to NAS2? Wouldn't this hypothetically give me 3 backup copies of my data?

 

[sfcredfox]

I would need to add an additional 3+2. This would allow me to lose 2 drives from Volume 1 and 2 from Volume 2 (4 total) and still have my data.
Is this correct?

That is correct, for each vdev, you can loose the parity protected number of drives. You cannot loose more drive in a single vdev than it's protected for. I.E. - You can't loose three drives in the same Z2 vdev. You can loose two drives in each vdev separately, but not three in any one.

Double check your use of the term volume. A volume can sometimes be interchangeable with pool (something mounted that can store data), but not vdev. A vdev is a grouping of disks and parity. A single vdev or multiple vdevs can make up a pool. You can read/write to a pool, but not to a vdev.

Your second question seems more about money/complexity. You could have two systems, sure. Mirroring is not backup though. A disk mirror is just that, what you do on one, is done on the other. You delete a file, that's mirrored. Mirroring is protection against hardware failure, not backup. Replicating your data to another system could be considered backup, as long as you don't immediately replicate file deletion. Again, accidentally delete a file on 1 and immediately replicating that to 2 doesn't help a lot. Snapshots are you friend for that though. Read up on that.

 

[Mr. S.]

Thank you for the replies.

I guess I got really excited about NAS and I am just now realizing that it probably is not exactly what I need for my situation.

You are correct. I am trying to do this build on the cheap so the cost of the build is an issue. My number one goal is backup. Redundancy is nice but I don't need a solution where my files are available 24/7. I like the idea of turning the machine off if I don't need to access it.

I think my best solution right now is to go with a simple linux build where I can add drives as I need them and I can use a backup utility to keep backup archives as files change. I should also be able to use rsync if I want to make a backup of the backup.

 

[sfcredfox]

Check out Open Media Vault, or a simple Ubuntu Server or whatever distro you like might work.