Setup Advice

[mgreeny]

Hello,

I was looking for some set-up advice. Tomorrow I'll be building FreeNAS for my home lab. I will be using it mainly for running VMWare disks over iSCSI. I'm trying to do this as cheaply as possible, reusing redundant (not old) hard drives. I'm getting a Dell T20, which has 6 HDD bays. These are the drives I have:

1x 256 SSD
1 x 1TB Disk
4 x 500GB Disks

How would you set up your raid arrays with the above? Is it best to use my SSD as cache disk? Include it in my RAID array? RAID Z1, Z2? I've noticed that due to the mix of sizes I will loose a fair amount of storage if I include my smaller SSD in the array.

Thanks!

 

[depasseg]

Which is more important to you - performance or capacity? If this is just a test lab, you can do whatever you want. If you want a little better random IO performance, use the 4 drives in a striped mirror (1TB usable). How much RAM do you have? You probably want 64GB or more to use the SSD as an L2ARC.

 

[BigDave]

Slideshow explaining VDev, zpool, ZIL and L2ARC for noobs!

And also
https://forums.freenas.org/index.php?threads/zfs-primer.38927/
ZFS Primer

 

[mgreeny]

Which is more important to you - performance or capacity? If this is just a test lab, you can do whatever you want. If you want a little better random IO performance, use the 4 drives in a striped mirror (1TB usable). How much RAM do you have? You probably want 64GB or more to use the SSD as an L2ARC.

I will have 16GB RAM in total. So SSD as cache not worth it with this amount of RAM? thanks

 

[mgreeny]

I will have 16GB RAM in total. So SSD as cache not worth it with this amount of RAM? thanks

Performance is more important by the way.

 

[Robert Trevellyan]

SSD as cache not worth it with this amount of RAM?

Correct.

1x 256 SSD

Boot drive, scratch pool, or put it in another box that can benefit.

1 x 1TB Disk

Scratch pool, or add another to make a mirror.

4 x 500GB Disks

You could argue for RAIDZ1 with 500GB drives, but if you plan to replace them with >1TB drives at any time in the foreseeable future, do it right and go with RAIDZ2 or striped mirrors.