10 x 2.5 bay DELL R630, looking for best pool design for iscsi ESXi SSD storage

[zimmy6996]

Its been a number of years, so i figured i should ask for the 2024 cliff notes on disk type and layout.

Im trying to build two identical storage systems. Both using R630 DELL chassis, 384gb ecc ram, dual E5-2697 cpus, and PERC H730P controller. My questions are:

1. Does the PERC H730P in HBA mode work correctly? It sounds like I should look to replace the controller with a HBA330. Im trying to handle the 10 2.5" bays.

2. The goal here is an iSCSI back end. I’d like to have a OS boot drive, 1 hot spare drive, and 8 drives available for the iSCSI pool. When I was using spinning disk, I was doing vdev mirrors, stripped together, which costs 50% of your physical space. With SSD performance now, and the IOPS it handles, can I get away with RAIDZ2 at this point, or am I sacrificing too much performance? Obviously thats a subjective question, based on workload. Consider the boardloads just standard windows server DCs, DNS, IIS, lower volumen general user servers. Nothing super IO intensive like heavy DBs. Just looking to strike the right balance.

[Davvo]

@zimmy6996

It sounds like I should look to replace the controller with a HBA330.

That would be my suggestion as well.

@zimmy6996

With SSD performance now, and the IOPS it handles, can I get away with RAIDZ2 at this point, or am I sacrificing too much performance?

Well… the suggested layout remains multiple mirror VDEVs, or at the very least multiple VDEVs… you could experiment with 2x 4-wide RAIDZ1 VDEVs.

I suggest reading this and this.

Ultimately, it depends on your hardware and your use case: not all silicon is born equal.

You can also consider dedicating a single mirror VDEV to iSCSI and using the remaining 6 in RAIDZ1 (or 2) fo more traditional protocols.

[ericloewe]

@zimmy6996

Does the PERC H730P in HBA mode work correctly? It sounds like I should look to replace the controller with a HBA330. Im trying to handle the 10 2.5" bays.

Expect it to be slow as molasses, in addition to being far less tested. The HBA330 mini is the way to go.

@zimmy6996

The goal here is an iSCSI back end. I’d like to have a OS boot drive, 1 hot spare drive, and 8 drives available for the iSCSI pool. When I was using spinning disk, I was doing vdev mirrors, stripped together, which costs 50% of your physical space. With SSD performance now, and the IOPS it handles, can I get away with RAIDZ2 at this point, or am I sacrificing too much performance? Obviously thats a subjective question, based on workload. Consider the boardloads just standard windows server DCs, DNS, IIS, lower volumen general user servers. Nothing super IO intensive like heavy DBs. Just looking to strike the right balance.

It’s not just performance. A lot of it is that RAIDZ cannot efficiently deal with small blocks. So, if you had small blocks on a RAIDZ2 vdev, you’d have the space efficiency of a three-way mirror with the performance of RAIDZ2. Naturally, this is bad.
So, my suggestion is “give it a try, but use large blocks”. Aim for 64 kB and absolutely stay above 32 kB. You’ll obviously need to set up the filesystems backed by this iSCSI extent accordingly.