What is the best use of my drives?

[tefoster]

I just went through a situation where I lost all of my information and it is time to start over. This time I want some sort of backup seperate from my main storage. I currently have 7 2T WD20EARS drives + 1 750G drive. I can fumble my way around the GUI to create a zpool but I am not familiar with any advanced command line commands. I do have one more 2T WD20EARS drives that I can fit in if it makes things work out easier. What is the best use of my drives and how do I go about getting it setup? I've been reading for a while now and I have found some good articles but none of them seem detailed enough for me to follow. I am not a *nix person but I can get things done with some guidance. The storage will primarally be used for multimedia, TV, Movies, Music, Pictures...

Thanks,
Tom

 

[Joshua Parker Ruehlig]

have you used freenas before? Theres very detailed guide to creating your zpool without touching the command line. I would go 8 x 2TB in raidz2 but your storage / data reliability needs may be different.

Also make sure to force 4k formating with your 2TB drives

 

[paleoN]

This time I want some sort of backup seperate from my main storage.

Does this mean you want a separate physical machine or ...?

 

[tefoster]

I guess that is what I am asking for help with. Should I go with 2Tx4 and mirror 2Tx4 or is 2Tx8 raidz2 a safe enough configuration? I know how to create the 2Tx8 but I don't know how to do the 2Tx4 and mirror it.

Thanks,
Tom

 

[Joshua Parker Ruehlig]

tefoster I'm not sure if I'd assume a mirror of 4 drives would be safer then a raidz2 of 8 drives. with a mirror if you lost 2 drives (one from each mirror) you'd lose your data, conversely you could also lose 4 drives from the same mirror and be fine. So I guess it's really variable which is more safe. (I wish statistics and data for this was more prevalent)

Raidz2 would perform better with sequential read / writes but mirrors would have an advantage with IOPS. RAIDZ2 has more of a CPU hit and would take longer to recover from a drive failure.

 

[paleoN]

I guess that is what I am asking for help with.

If you are building 1 FreeNAS box I would go with Joshua's first suggestion of 8 X 2TB WD20EARS in raidz2 giving you 12TB raw. You would need to lose 3 drives at the same time before you lost the zpool.

How much space do you need? I now remember reading your zpool FAULTED thread. I suppose a second local pool would help protect against that. Though by that point I would prefer to have a 2nd FreeNAS box to replicate to.

 

[tefoster]

Thank you all for your suggestions, It looks like I'm going with the 8 X 2TB WD20EARS in raidz2 configuration.

Thanks,
Tom

 

[paleoN]

Just a word of warning, make sure all of your 2TB WD20EARS are healthy. You will be much better off running with 6 healthy X 2TB WD20EARS raidz2 than running 8 X 2TB raidz2 with a few marginal drives tossed in.

 

[tefoster]

paleoN,

Can you please elaborate on your last comment, I don't understand why a 6 drive array is better than an 8 drive array with marginal drives?

All of the drives are good, after my recent disaster I did a thourough test of all the drives and RMA'd all of the faulty drives back to WD. So currently all 8 drives are healthy.

Thanks,
Tom

 

[paleoN]

If all of your drives are healthy then you are good to go.:)

A 6 healthy drive array is better because all 6 drives are healthy!

Oh, and what I meant by marginal drives are ones that have or had errors or are acting flaky in some fashion. In other words they are on a short road to death or causing corruption. While Raidz2 protects you from 2 bad drives it would essentially mean you are running with no redundancy if something happened to one of your other drives.

So in my example the 6 drive array was better because all the drives were good. Not because a 6 drive array is better than an 8 drive array.