New User – Quick advice…

[RichD]

Hello – I’m creating my first FreeNAS server and would like a quick piece of advice.

I’m using a 1U dual xeon server with 12G of ram. I have 4 WD RED 1TB drives going in it.

My goal is redundancy and security of my data. Performance is not important to me.

My question is, which setup configuration do you recommend for the ultimate in redundancy and data loss protection?

Ideally, I would like it to take all four drives failing before I lose any data.

Thanks for any advice.

 

[Mirfster]

I have 4 WD RED 1TB drives going in it.

My goal is redundancy and security of my data. Performance is not important to me.

I would recommend RaidZ2 personally. Others may suggest differently.

Ideally, I would like it to take all four drives failing before I lose any data.

Impossible, no way you can lose all the drives and expect to have any data. But, that is why backups are recommended.

 

[mattbbpl]

Technically, I think he means he wants to be able to lose 3 of the 4 drives and still have data which he could do by using RaidZ3. Note that you'd be sacrificing a lot, OP, to the point that you'd actually have less than 1 drive's worth of capacity in the scenario you laid out if you did this.

 

[Mirfster]

I was just thinking to myself that I should not have replied. Instead, I should have waited to see if jgreco provided one of his classic responses...

Technically, I think he means he wants to be able to lose 3 of the 4 drives and still have data which he could do by using RaidZ3. Note that you'd be sacrificing a lot, OP, to the point that you'd actually have less than 1 drive's worth of capacity in the scenario you laid out if you did this.

Agreed, but to me that is actually well beyond the "point of diminishing returns". Hence my RaidZ2 recommendation.

 

[joeschmuck]

My question is, which setup configuration do you recommend for the ultimate in redundancy and data loss protection?

You have a few options because you didn't make any real specifications on how much data you desired to store so I'll take it one step at a time...

1) Maximum redundancy: Mirror of four drives - Allows three of the four drives to die plus gives you great throughput - Downside is you have under 800GB of storage.
2) Similar to a mirror is the RAIDZ3 which allows for three drives to fail, similar to the mirror however it's not as speedy.
3) If you need more storage than 1TB then you must go with RAIDZ2 which affords up to 2 drive failures and you will retain your data.

 

[Bidule0hm]

which he could do by using RaidZ3

Nop, RAID-Z3 needs at least 5 drives (4 for RAID-Z2 and 3 for RAID-Z1) :)

He can do what he wants with a 4 way mirror but that's 75 % of the raw space used for parity...

 

[Mirfster]

Nop, RAID-Z3 needs at least 5 drives (4 for RAID-Z2 and 3 for RAID-Z1) :)

Oh yeah, there is that stickler too...

 

[mattbbpl]

You have a few options because you didn't make any real specifications on how much data you desired to store so I'll take it one step at a time...

1) Maximum redundancy: Mirror of four drives - Allows three of the four drives to die plus gives you great throughput - Downside is you have under 800GB of storage.
2) Similar to a mirror is the RAIDZ3 which allows for three drives to fail, similar to the mirror however it's not as speedy.
3) If you need more storage than 1TB then you must go with RAIDZ2 which affords up to 2 drive failures and you will retain your data.

I had no idea you could have multiple mirrors of the same drive. That actually opens up a lot of options where both speed and redundancy are critical (albeit at the cost of extreme capacity loss).

 

[joeschmuck]

Yea, and I forgot about the RAIDZ3 drive minimum although I thought it could be done manually, eh, I'd choose the mirror for the redundancy and speed. That storage does come at a premium however that was the question asked.

 

[Mirfster]

Eh, just go to the cloud and be done with it...

 

[RichD]

Thanks everyone for the quick replies and advice. It's great to know there is a good community here willing to help!

I'll debate going with the full mirror (but losing a lot of capacity) or with raidz2 which gives me more space and can still handle two drives failing.

Even if the full mirror gives me 800GB, that's still double what I'm using on my current server so not so bad. I'm leaning toward getting greedy on space and going with raidz2 (even though that's a bit different than what I said in my original post).

Thanks much!

 

[diedrichg]

RAIDZx or Mirror can not survive a disaster if you don't have a backup drive or other backup solution.

 

[mattbbpl]

Personally, I'd go with RaidZ2 (that's actually what I'm using with a much higher capacity and drive count).

That comment alone isn't worth me chiming in again, but the following is:

You state that you are currently only using half of the current mirrored capacity. If planning for future growth, you want to plan to fill it no more than 80% capacity. You can go a little higher than this if your performance needs are slow and you aren't at risk of filling your pool, but with such a small capacity I wouldn't recommend it.

 

[Robert Trevellyan]

forgot about the RAIDZ3 drive minimum although I thought it could be done manually

It can, it just doesn't make any sense.

 

[joeschmuck]

It can, it just doesn't make any sense.

Since when do all users make sensible decisions? ;)

 

[Ericloewe]

Eh, just go to the cloud and be done with it...

Obligatory xkcd: http://xkcd.com/908/

Whenever you are going to say "cloud", replace it with "tiny box in this guy's office running off a cable modem" and base your risk analysis on the revised statement. :D

 

[Mirfster]

Lol, good point. :)