FreeNAS Box Disk Strategy

[gabster]

Hi gang!

freeNAS newbie here.

So I am planning to build a new freeNAS box with five 3T drives, where two of them I already use in my Synology NAS (up to 90% capacity already). What's a proper strategy in this case?

1. Dump everything I have on the two drives somewhere else temporary until I set up the 5 raid box?
2. Keep everything on those two drives, add them to the other three, and install freeNAS on top? Will all data be erased?

thanks
g

 

[Linkman]

Move the data. All the data drives will be erased when FreeNAS builds the pool.

 

[gabster]

Thanks a lot!!

That's all I needed to hear.
cheers!

g

 

[Mirfster]

until I set up the 5 raid box

Please don't tell me you are thinking of RaidZ1.....

 

[gabster]

Honestly - I wasn't thinking of any raid configurations as of yet. I was too taken up with the hardware.
But... why not RaidZ1, @Mirfster ?

thanks!

 

[Bidule0hm]

Because of this: http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/

 

[Mirfster]

RaidZ1 is basically the same thing as traditional Raid5. So you only have 1 drive for redundancy. So say one drive does go bad and you replace it... Well as it is re-silvering there is a increased probability (mathematically due to drive sizes nowadays) that an second disk could fail during this. Well, then that means loss of the vDev. Which in turn means that ANY pool that vDev is a member of (whether it is just a pool made from one vDev or a pool made of 100 vDevs) is toast...

There are tons of threads where it is NOT recommended (just search for "RaidZ1"). This is a link @cyberjock keeps in his signature called RAID5/RAIDZ1 is dead. As well, if you look at cyberjock's Slideshow explaining VDev, zpool, ZIL and L2ARC for noobs! you will see mention of it there as well. Overall, it is not a good idea; especially with today's hard drive sizes.

 

[gabster]

Ouch -
RaidZ1 hurts indeed.
So, considering that I am after maximizing speed and storage performance (working in video editing) what would be my options with 5x 3Tb disks?

 

[Mirfster]

I am a fan of RaidZ2, seems to be the best balance of Speed, Redundancy and Space for me.

But, since you are video editing you may consider using a 2 - 3TB Mirrors with the 5th disk as a Global Spare... Of course in that setup you would have a total of 3 disks basically just for redundancy. Still a bit scary for me personally.

RaidZ3 would also allocate 3 drives for parity, so that would be the safest; but also the slowest of them. Not sure by how much though (never really tested the actual speeds).

Maybe others can offer another route, but that is all I can think of for 5 drives. If you haven't already, please do take the time to go over the Slideshow explaining VDev, zpool, ZIL and L2ARC for noobs! it is very informative and worth at least one read (if not more)

 

[gabster]

Thanks a lot @Mirfster. That's precious info in that slideshow (I am going through it right now - lots to digest). My first option would have been a DAS (direct attached storage), since speed is vital in video editing environment (hefty 4k footage, using daVinci Resolve for grading) along with space, but since my iMac doesn't have anything beyond Firewire 800 speeds, NAS was the only fastest option (theoretically 125MB/s).
At this point, I could practically have the RaidZ2, since it makes sense (in the slideshow they estimate it to be safe till 2019). I am the only one using the machine so the risk of others screwing things up is low.
thanks for the help!