Using RAID controllers with Zos

Zero OS prefers to have direct access to disks. When there’s a RAID controller in your system, the best configuration is a mode that passes direct disk access to the operating system. These modes are called JBOD “just a bunch of disks”, HBA “host bus adapter”, or IT “initiator target”.

If your RAID controller does not support one of these modes, then the best approach to to create a RAID 0 array for each individual disk, occupying the full disk. This may impair performance compared to the preferred modes listed above, but it should allow Zos to find and utilize the disks.

Reflashing Dell RAID controllers

Thanks to a couple members of our community for pointing out that some Dell RAID controllers can be reflashed with different firmware to add support for a passthrough mode. Please see the instructions here, and proceed at your own risk :wink:


For the common hp raid controller p420i you can follow these steps.

If you don’t have a RAID controller that has a HBA mode, hackable or otherwise, LSI cards with internal mini-SAS plugs are a good cheap alternative.