Setup suggestion

[JohnFLi]

I have a physical device that I can stuff 30 10TB western Digital Gold drives in.

I am looking to create a useable data space of 190TB. This space will be used as a target location for backup jobs to go to, so it doesn't need to be super fast.
10 gig network connection.
The share will be via SMB.

I know little about freenas and Raidz(s). I'm sure I could just use 20 10TB drives and make a single RaidZ1....but I seriously doubt that is recomended (which is why i am asking)

what would be a good reliable setup to accomplish my goal of having 190TB of usable space?

 

[nightshade00013]

Ok, the good thing is that it can be done with a RaidZ2 with three 10 drive vDev's.

The bad thing is that it has been said that once we get over a certain size drive the risk of URE's is a lot higher and even RaidZ2 will not be safe so if you do it that way you will be taking a risk so keeping a couple spare drives on hand that are tested and ready to go would be very wise. And even better is hot spares or using RaidZ3 but you will fall just short of your goal with only 30 drives available. Personally I would see if I could stow a couple more drives and run 3 vDev's of 11 drives in a RaidZ3. With the case I have now I am planning to go to a 12 drive RaidZ3 and eventually run a couple vDev's in that, gotta love that 48 bay case.

You could run a RaidZ3 with two 15 drive vDev's but it has been suggested that 12 drives should be considered an upper limit. I would still keep spares on hand since the loss of a vDev looses the pool.

http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/
http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/

 

[JohnFLi]

Thank you for your suggestion. If I end up running a little short, that will be fine i suppose. (I would only be licensed for 190TB max anyway, so if i'm shy of that, its ok)
I'm stuffing these into a 60 bay case ;)

 

[Ericloewe]

(I would only be licensed for 190TB max anyway

What?

 

[JohnFLi]

Sorry, I guess I should have expanded on that part a bit. The reason I wanted 190TB blob is because it is going to be the target for commvault de-dup backups to disk. We are going to get a license to backup to disk for 190TB. With commvault you get limited on backing up to disk

 

[nightshade00013]

So I am guessing that you will back up all of your data on the FreeNAS to their service.

Just add a couple drives since you have a 60 bay case and go from there. With that much data in one pool I wouldn't want to do anything other than RaidZ3 myself. Some 12 Drives vDev's and you would be all set. Having a couple hot spares would still be advisable if you are really paranoid. Below is a calculation with the Practical Capacity leaving 20% free which should work pretty well.

RAID type: RAID-Z3 (Triple parity with variable stripe width)
Number of RAID groups: 3
Number of drives per RAID group: 12
Total number of drives: 36
Drive capacity (GB): 10000
Drive capacity (TiB): 9.094947
(TiB) (%)
Total raw storage capacity: 327.418093 100
Zpool storage capacity: 327.000000 99.87
Reservation for parity and padding: 89.181818 27.24
Zpool usable storage capacity: 237.818182 72.63
Slop space allocation: 7.431818 2.27
ZFS usable storage capacity: 230.386364 70.36
Minimum free space: 47.563636 14.53
Practical usable storage capacity: 182.822727 55.84

 

[JohnFLi]

Currently, I'm using half the bays for other stuff, some regular smb shares, and some with iScsi. so 30 slots is all i got left. What I will most likely do is start off with a handfull of drives, and expand as needed. at a little under $500 per drive, i doubt I'll be able to get 30 drives at the time