I'm successfully using Solaris 11 as my development OS on my x64 workstation. Hardware is: Supermicro X9SRA, Intel Xeon E5-2620, Kingston registered ECC RAM 32GB, 1x OCZ Vertex3 SSD on SATA III and 2x Hitachi 7K500 500GB drives both on SATA II connectors.
Now, I've installed Solaris 11 11/11 and everything behaves (w.r.t. hard-drive led) normally. Then I performed first update which was offered by update manager, this was still update where OS presented as 11.0. And even after this upgrade HDD LED was behaving normally. Then after second update when the OS starts to show as 11.1, this is where issue comes. Hard drive LED behaves normally up to some point after the kernel boot messages are printed and then its just switched on for all the time. I'm verifying that there should be no activity on drive by using zpool iostat 1 and iostat 1 tools. So even when drives (all three) should be idle from the point of view of those two utils, the drive LED is still switched on like the drives are serving some requests. Please note that if I reboot to Solaris 11 11/11 or Solaris 11 (first update) BE, then this behavior is not presented and LED lights just when drives are doing some work, so I guess hardware should be all right...
Do you have any idea what's happening or how to solve this issue?