We’ve seen a spate of incidents recently related to the HP Smart Array Drivers that are shipped as part of ESXi 5.x. Worst case scenario – this is leading to out of memory conditions and a PSOD (Purple Screen of Death) on the ESXi host in some cases. The bug is in the hpsa 22.214.171.124-1 driver and all Smart Array controllers that use this driver are exposed to this issue. For details on the symptom, check out VMware KB article 2075978.
HP have also released a Customer Advisory c04302261 on the issue.
This was a tricky one to deal with, as one possible step might be to roll back/downgrade the driver to an earlier version. Unfortunately, not only is this not supported (or documented), but you might also find that an older driver may not work with a newer storage controller. The good news is that HP now have a new version of the driver available which fixes the issue. Customers should upgrade to HP Smart Array Controller Driver (hpsa) Version 126.96.36.199-1 (ESXi 5.0 and ESXi 5.1) or Version 188.8.131.52-1 (ESXi 5.5). Details on where to locate the driver and how to upgrade it are located in their advisory. Think about doing this as soon as possible.