RAIDZ config options

[els]

I posted a message a while ago, probably last year, inquiring about whether I could use NAS as datastore for VMWare ESXi and after some research I decided against it. VMWare ESXi server now has its own RAID controller (RAID 10) and I'm happy with the results. I'm getting parts to build NAS server and I'm waffling about RAIDZ configuration options. The chassis I'm getting has 10 hot-swap bays and I'm going to go with WD Red. I'm not worried about hardware selection (server grade components).

Config options:

• 6 or 10 drives using RAIDZ2 (probably the best option) I'm leaning towards 10 drives
• 8 drives using RAIDZ2
• 9 or 10 drives using RAID3 (not optimal but will work)

I've thought about splitting into two vdevs for better IOPS (but worse throughput) and I think I'll stick with single vdev.

Comments? Thoughts?

 

[SwampRabbit]

It may not be the perfect answer, but something I can share is that the new Initial Configuration Wizard in 9.3, may have the answer for you.

The wizard provides several options when creating the pool:

• Automatic - Pick reasonable defaults for available drives
  
• Visualization (RAID 10: Good Reliability, Better Performance, Minimum Storage)
• Backups (RAID Z2: Good Reliability, Medium Performance, Medium Storage)
• Media (RAID Z1: Medium Reliability, Good Performance, More Storage
• Logs (RAID 0: No Reliability, Best Performance, Maximum Storage

Based on this you would want a RAID 10 or a striped mirror with a minimum of 4 disks in each group.
This provides you with better reliability than with a RAID Z1 versus no reliability with RAID 0, while still getting good performance for your use case.

You could do a RAID 10 with 8 drives and have two spares available.

 

[Jailer]

10 drive RAIDZ2 if you have the space for it. If I were starting over right now that's what I'd do.

 

[els]

Thanks. I'm thinking 10 drive RAIDZ2 is the best option for my use cases. I plan to keep all movies, music, backups (VMs for work projects), etc. I don't really need high-performing NAS and I believe 1 gigabit Ethernet would be the bottleneck regardless of what RAID configuration I choose. How much impact on performance if I went with 10 drive RAIDZ3? I know it's probably not optimal configuration.