Recently stumbled across a problem with DataCore's MPIO on Server 2012. The release notes of HIK v. 1.0 update 1 clearly state full support for DataCore MPIO on Server 2012. Checking the Host Software Qualification List from DataCore you can see that HIK is not supported under Server 2012.
Only native Windows MPIO is supported. Well, this wouldn't be a big problem if the native Windows MPIO wouldn't suffer a problem with rediscovering a failed path. The notes for native Windows MPIO on Server 2012 clearly state:
"A manual ‘device rescan’ may be required to re-discover any previously failed paths to the DataCore Servers"
This isn't what I expect from a fully automated failover for which I use MPIO!!
I had this problem many times in productive environments where only native MPIO from MS was used and I nearly always had to rescan manually to rediscover a failed path. Sometimes the failed path will be rediscovered without manual interaction but you have to wait 30-60min. No way in a upgrade session where you have to reboot DataCore servers often.
I contacted DataCore support to get a definite answer on which MPIO to use and got the answer that currently only the native Windows MPIO is supported.
Update: DataCore support corrected itself and states now that the Host Software Qualification List is out of date. There is full support for Windows Server 2012 with HIK 1.0 Update1.
The Qualification List will get updated asap to correct this error.