ESXi and HBA RAID

[StephanZ]

I'm planning to build a small virtual environment based on ESXi for experimentation and educating myself. The plan is to use the following HBA (build in support for RAID 0, 1, 10): SAS 9217-8i

The RAID will be build with:

1) Two 3TB HDD RAID 1

2) Two 500GB SSD RAID 0

My concern is that since the HBA does not have memory for caching and BBU the performance will be really slow.

Also the VMWare compatibility hardware site lists the HBA as SAS device. Are there any problems with ESXi and HBA RAID arrays.

Thanks

Stephan

[sk84 · Accepted solution]

Also the VMWare compatibility hardware site lists the HBA as SAS device.

Yeah. Because it's a SAS HBA. 😉

My concern is that since the HBA does not have memory for caching and BBU the performance will be really slow.

You will not get any performance benefits but the performance should not be worse then the slowest hard disk. And with a missing BBU you will only risk loosing some IO during an power outage of the server. In my opinion, these restrictions are justifiable for a homelab.

Are there any problems with ESXi and HBA RAID arrays.

As long as this HBA card is on the HCL, there should be no problems. But it is important to use a supported driver / firmware combination. See: VMware Compatibility Guide - I/O Device Search

The RAID will be build with:

1) Two 3TB HDD RAID 1

2) Two 500GB SSD RAID 0

I would consider whether I really want to make a RAID0 for the SSD Datastore? The performance gain is relatively unimportant in this case and you have double the storage space, but if an SSD dies all VM data on this data storage are lost. Usually it makes more sense to configure 2 single datastores with one SSD each. If one SSD fails then at least not all data is gone. And you can also distribute the virtual disks over both datastores.

[StephanZ]

Thank you for the detailed answer!

I'm perfectly OK with the setup since the performance should not be worse then the slowest hard disk. The SSD disks will be used for playground and each VM will live there only for couple of hours. Everything that is useful will go to the HDD RAID.

BR,

Stephan