ZFS Pools

[gomer23]

I have been reading alot about Freenas 8 and ZFS over the last week. I am building a box for a friend for him to store 3D video renders to. Right now they want to build the box and start with 3 drives. So I was going to get 3 2TB 7200RPM drives and put them in a raidZ configuration with a volume and then whatever shares they want. Down the road when we add lets say another set of 3 drives I would put those into another raidZ configuration correct? And add that to the pool. From there I am not sure how this works, do I then have the shares go from the ~4TB to ~8TB or will I have to do a separate set of shares? If they do act as 1 volume what does that do for redundancy, could I have 1 drive fail on each set and not lose anything or?

I tried to search around for details on this but figured I would ask to get a more direct answer. If there is a thread about this that I missed you can point me that way. Or if someone has a better recommendation on the setup let me know. Thank you.

 

[cyberjock]

Check out the powerpoint in my sig.. it will answer all of your questions :)

 

[gomer23]

Perfect that is exactly what I was looking for. Thank you for the lnk!

 

[cyberjock]

No prob! Glad it helped :P

 

[gomer23]

Oh it did. I actually just finished it. So just to confirm then. Since if one Vdev were to fail. I.E. I have 2 drives in a 3 Drive raidz1 then I lose all of the data even on the other vdev. I get that so, just so I understand then when I write something to the pool the data is getting written between the 2 vdevs and not to just 1 of them. I hope I am asking that clearly enough haha.

 

[cyberjock]

Big picture the data isn't necessarily striped evenly across the vdev. If you save a 100MB file it might be stored on 1 vdev or both. Maybe not even evenly distributed. What's important to keep in mind is that if any vdev goes offline your entire zpool is lost. ;)

 

[gomer23]

That answer works for me. I was more just curious how the data was written between devs at that point. And like you said main point to take away is, don't lose one of the devs haha.

Thanks again for your help!