Jayakara Kini's Weblog: Jayakara Kini's Weblog

Logical Domains support was integrated into Solaris Nevada on May 16th.  With Logical Domains (LDoms), it would be possible to simultaneously run more than one instance of Solaris on one box.

LDoms is supported only on sun4v systems (with UltraSparc T1 processors).  So, why is only sun4v systems supported?  Thats because the UltraSparc T1 processor has Hypervisor support built in.  The firmware on sun4v systems also support it.  At this time the there are only two sun4v models: T1000 and T2000.

LDoms support for Solaris 10 is being integrated sometime in the next month.  After that both Solaris 10 and Solaris Nevada can be run simultaneously on one system.

To use the LDoms features:

• Upgrade the firmware to the latest release.
• Upgrade the Nevada release to build 41 or later (build of 17 May 2006 or later would also do)
• Install the LDoms Manager (code name: Zeus) which is bundled separately.

At the time of writing this, the firmware and the LDoms manager is not available outside Sun.

I have some doubts here for which I did not find any documentation:

• Does LDoms require at least one CPU per domain or can one CPU run multiple OSes.  If it does require one CPU per domain, then T1000 will not be able to run LDoms as it has only one CPU?
• Is there is a limit on the number of domains that can be run on a box if there is no requirement of dedicated CPUs for a domain?
• When will the new firmware and LDoms manager be available for all?

Well, I guess these would be answered soon.  Anyway, the possibilities of its usage, combined with Zones, is numerous.  I have been amazed by some of our customers who use Solaris in ways we did not even think is possible.  With LDoms and Zones, I'm sure it'll keep happening...