RAID controllers are great if you're using them to do the thing that they do. If you are going to host a software defined storage solution on top, then the thi

RAID controllers are great if you're using them to do the thing that they do. If you are going to host a software defined storage solution on top, then the thing RAID controllers do for you (abstract the hardware storage devices into a block volume device) becomes counter productive. Most modern array controllers can be switched to HBA mode, which disables the RAID bits entirely and passes SAS/SATA commands through directly to the device. The article doesn't say if this was done, but based on the description of events, it wasn't. Running software defined storage on top of hardware RAID functionality is begging for trouble.