best way to setup six 2tb drives in zfs?

[wkearney99]

I've got a 4 drive RAID5 array of 2tb discs on a windows box. I'm looking to move that 6tb of data over to an OpenIndiana server. I've got six new 2tb drives to use for it.

What would be the best way to arrange the drives? I'd like to get at least the same 6tb capacity but would prefer better performance. Would arranging them in three 2-drive mirrors be a good idea? Or two 3-drive raidz, mirrored?

I'd be able to add at least one more 2tb drive as a hot spare, possibly two as the controller has 8 ports.

 

[danswartz]

What is your job mix? Read heavy? Write heavy? Balanced? Striped mirrors have very good random read performance due to balancing reads across the mirrors. A 3x2 mirror would give you good read performance and the same amount of space, but a 6-disk raidz2 would give you 4 drives worth of data instead of 3, and be able to lose any 2 drives and still be okay, but the random IOPs will not be as good.

 

[wkearney99]

It's mostly office and development work; a mix of a lots of reads and some writes. I'm guessing cache will do a lot to improve the situation. I'm just sick of only getting under 40MBs for single client access when accessing a lot of files. With multiple clients into a windows box performance just tanked. This has more to do with the crappy windows setup, of course, but since I've got the chance to "do it right" I figured it was worth asking. I've been using a hardware RAID5 + spare setup and it's been great for reliability. From what I gather the 3x2 mirrors would stand to provide considerably more IOPS, but I'd worry about availability in the event of drive failure(s). So I kind of wondered about doing a mirrored raidz as a way to get greater IOPS while having a greater degree of availability in the event of drive failure.

 

[jonnyjl]

It's mostly office and development work; a mix of a lots of reads and some writes. I'm guessing cache will do a lot to improve the situation. I'm just sick of only getting under 40MBs for single client access when accessing a lot of files. With multiple clients into a windows box performance just tanked. This has more to do with the crappy windows setup, of course, but since I've got the chance to "do it right" I figured it was worth asking. I've been using a hardware RAID5 + spare setup and it's been great for reliability. From what I gather the 3x2 mirrors would stand to provide considerably more IOPS, but I'd worry about availability in the event of drive failure(s). So I kind of wondered about doing a mirrored raidz as a way to get greater IOPS while having a greater degree of availability in the event of drive failure.

mirrored raidz? So you're introducing hardware raid?

Go 2x3-way mirror if you're concerned about failure. Cuts your available space down a bit, but meh that's always going to be the trade-off in any type of "RAID" system. Keep a hot spare if you can, if not keep some cold spares around.

 

[Silenus]

Since you moving data over from existing storage...just test it first. I'd go all 6 drives in RAIDz2 to start with. See how that goes before other configs. That gives you 2 drives of parity, 4 drives capacity and decent read performance. With enough ram...and maybe even an inexpensive 60GB SSD as L2arc you may be fine if you are read heavy.