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FreeNAS RAID suggestion


I am building a “new” server with FreeNAS for my main storage. It contains 12 of 3TB SAS drives, they all used. This will be my main storage server so I am not sure which RAID configuration I should choose from.

3x 4 drives raidz1 in strip (~raid50)

2x 5 drive raidz2 in strip (~raid60)



moved to storage hardware category



How many drives do you plan to add down the road?

How about 12x raidz2? … Use some high endurance SSD for cache and log disks.



Not sure yet. It’s a 16 bay server. I will add a 1TB NVMe drive for cache at some point.(will run at PCie gen2 tho)
12 drive raidz2 will take forever to rebuild and more chance to have a second drive failed. On top of that, the performance will be much lower compare to other options. That’s why its not in my consideration.



My mantra (circa 2011 or so): RAID 5/RAIDZ should be avoided in all modern setups.



Not sure what your workload is. Personally, I would go with Mirroring, but if you want RAID Z, I will recommend RAIDZ1 with 3 drives per vdev for a couple of reasons:

  1. You can use the remaining drives as hot spares. You mentioned that they are used, so its probably a good idea to keep spares, in case a drive fails.
  2. Future expansion. Instead of buying 4 or 5 drives when you need to add another vdev to your pool, you can get away with buying three at a time.


Hi, I’ve also recently made a FreeNAS build. I want to saturate my 10Gbe while using RAIDZ2. Is 6 drives enough or do I need to hit 10 for the vdev?