ESXi 6.0 hosts connected to Dell Compellent SCv2000 via SAS experience an issue where by the LUNs do not survive a reboot. A rescan of the HBA's doesn't detect any LUNs.
Removing and re-assigning the LUN mappings for the hosts in Compellent Enterprise Manager works until the hosts are rebooted again.
Turns out that the 12Gb SAS HBA supplied by Dell is manufactured by Avago. The ESXi 6.0 2b image from the VMware website doesn;t have any inbox drivers from Avago so instead uses the LSI-MPT3 SAS driver. Whilst this appears to work from the outset, a reboot of the hosts proves that connectivity to the array isn't re-established after a reboot.
The solution is to remove the LSI-SAS VIB from the boot bank and install the Avago driver which can be downloaded from the VMware website:
After the package has been downloaded you will need to extract the offline bundle file with the ZIP extension and copy it to a VMFS datastore, in my example this is 'vol1'
Use putty etc to SSH onto the host(s). The first command removes the LSI-MSGPT3 VIB, a reboot is required afterwards. The second command installs the Avago VIB
esxcli software vib remove –n lsi-msgpt3
esxcli software vib install -d /vmfs/volumes/vol1/mpt3sas-10.00.00.00-6.0-offline_bundle-2803883.zip