VSAN RAID controller hw compatibility

arkadiy · ‎09-08-2016

Hi

Can someone explain this. So i have a Dell R430 server. It has a RAID controller that is not on VSAN HCL. There are controllers for this server (more expensive ones) that are on HCL. Clearly because its not on HCL, VSAN health checks give me a warning. However the drives used for VSAN are not part of any RAID (i went to controller settings during bootup and made drives non-RAID as expected for VSAN) and RAID 1 presented by this controller is really for ESXi local hypervisor install. So what is the meaning then of RAID controller being or not being on VSAN HCL?

Thanks

Arkadiy

TRottig · ‎09-08-2016

Are you using any of the drives on this Raid controller for VSAN? Then o/c VSAN will check the HCL for the controller as its a root device for the drives attached.

If not (i.e. the Raid controller is only used for driving the OS drives) then its potentially a bug.

zdickinson · ‎09-09-2016

Good morning, I believe you're asking why does the RAID controller need to be on the HCL if you're not doing RAID. Instead of RAID controller, think of it as an IO controller. All of the IO for vSAN will be going through. So it is important that it has been tested for vSAN. As an aside, please get the largest queue depth as possible. Thank you, Zach.

MBrownWFP · ‎09-09-2016

As Zach mentioned, storage controller queue depth is very important for VSAN.

A controller that is not on the HCL may work, but when I/O gets busy you will likely run into issues with controller performance which will directly affect your workloads running on VSAN.

arkadiy · ‎09-09-2016

Hi

Ok so i am not sure how things are physically configured, but what i did on RAID controller setup (break boot cycle) is marked those drives as non-RAID. With that i am not sure if for VSAN this still think drives are being presented by controller or not. They show up as raw drives and i add them to VSAN.

Regards,

Arkadiy

arkadiy · ‎09-09-2016

Ok i see your point. Fair enough, yes drives are non-RAID and are presented raw to VSAN, but you are saying because data still goes through this controller, it does need to be on HCL. Certainly whether i am doing RAID or not, there has to be some sort of IO controller to direct traffic to multiple drives. I think that makes sense, thank you.

depping · ‎09-11-2016

For VSAN it is simple: Disks used for VSAN need to be on the VSAN HCL Flash used for VSAN needs to be on the VSAN HCL Disk Controller which has disks connected to it which are used by VSAN needs to be on the VSAN HCL Having said that, a controller which is only used to boot ESXi from for instance does not need to be on the VSAN HCL, but that needs to be on the vSphere HCL. All of the above is the key reason I usually recommend people to go with a VSAN ready node. As this avoids running in to unsupported configurations.

arkadiy · ‎09-12-2016

Dunkan

Ok so if controller is only used to boot ESX and does not need to be on VSAN HCL, if VSAN health check gives me a warning about that, is that a bug? This is a POC / demo environment, VSAN ready not will not apply here. I just need to understand what is expected and what is not.

Thanks

Arkadiy

zdickinson · ‎09-12-2016

I there are no vSAN drives attached to the controller then it does not have to be on the vSAN HCL. It would still need to be on the ESXI HCL.

Either way, if it's a POC it should be fine. But if you have bad performance and/or issues, don't necessarily blame that on vSAN.

Thank you, Zach.