HP MSS/DataVaultにWHS2011を入れた際に、LEDランプを光らせることの出来る勝手ドライバーの最新バージョンが公開されています。今回のバージョンから、おそらくH34xでも動くだろうとのことです。

Hp Ex48X Lights Management Driver For Whs 2011 – We Got Served Forums – Page 6

既知の問題やFAQは以下を参照のこと。

Know limitations and FAQ
3TB and/or GPT partitioned disks not propely detected
The problem is probably more GPT than 3TB (though GPT needed for 3TB). I will do some tests.
Stablebit DrivePool and maybe DriveBender
The drives will blink if they are not managed by WHS because WHS tells me the drives are not allocated to WHS. I plan to make the lights configurable in the config file so users with special needs will be able to override the default light behaviour.
Windows OS compatibility
Only Windows Home Server 2011 has been tested. Should also be compatible with Windows Small Business Server 2011 Essentials and Windows Storage Server 2008 R2 Essentials.
Lights-Out
There were issues with Lights-Out but I made changes that should solve the problem.
Windows Mirrored drives
The Storage Manager service will only give me a Data status for one of the mirrored drives. The other drive will be healthy but unallocated. By design the disk LED will blink. I plan to make the lights configurable in the config file so users with special needs will be able to override the default light behaviour.
Blinking LED drive
This is by design, the drive LED will blink if you have not assigned any partitions to the drive, it is not assigned as a backup drive, or the drive is mirrored or assigned to Stablebit DrivePool (and probably also DriveBender).