Tuesday May 01, 2007

LDoms 1.0 is out!

As Ash and Narayan have already announced, Logical Domains 1.0 is now a reality!

Tuesday Mar 06, 2007

Logical Domains 1.0 Early Access Now Available!

It's here! LDoms 1.0 Early Access has just been posted to the Sun Download Center. This 68+ MB tarball includes new firmware images for T1000, T2000, Netra T2000 Server & Netra CP3060 Blade systems; mandatory patches to Solaris 10 11/06 (aka Update 3); the unbundled LDoms Manager & security packages; documentation; and an install script. In addition, a Sun BluePrints article entitled Beginners Guide to LDoms: Understanding and Deploying Logical Domains is available separately.

This is Early Access software. As stated on the download page: "This is an unsupported technology preview of Logical Domains software, providing early access to those interested in the technology". In other words, there are known bugs, limitations & rough edges (all of which we're working hard to eliminate for our 1.0 General Availability release later this spring).

As the LDoms Manager team lead, I'm very excited to help make this technology available for folks to try out. Everyone on the LDoms team is thrilled to have reached this major milestone, and we all look forward to hearing about the experiences of all our early adopters. We welcome your feedback (ldoms-feedback AT sun DOT com) to help us improve the product, and you can participate in the discussion at the LDoms SysAdmin Hub on BigAdmin.

Tuesday Jan 02, 2007

LDoms features in Solaris

LDoms features are showing up in Solaris 10 11/06 (aka Update 3); this does not mean LDoms is now available.[Read More]

Wednesday Oct 25, 2006

What I do at Sun

Whenever I'm asked by family & friends to describe what I do at Sun, unless I'm talking to other engineers, my description of my job & current project usually leaves my audience with that glazed look in their eyes. My hope is that with this blog, I can describe my work, and the immense satisfaction I get out of it, in a way that's approachable to all interested. So I'll start here with a high-level, not too technical description of what I do, then dive into more technical details in future posts.

I lead a small team of developers working on software that configures and manages a set of computer systems. But instead of each of these "systems" being a separate physical computer, they're all running on the same machine! This is possible partly through a technique called virtualization, which allows one computer to run multiple operating system (OS) images simultaneously. Each OS thinks it's running on its own physical computer system, with CPU(s), memory, disk, console terminal, and network connection(s). This illusion of a complete computer system is sometimes called a "virtual machine". We call it a "Logical Domain" (LDom for short). The OS image running in an LDom is termed a "guest" OS. To someone logging in to a LDom, it is indistinguishable from logging in to a separate machine running the same OS.

We actually accomplish this through a combination of partitioning and virtualization. Since the computers our project utilizes contain lots of CPUs and memory, we can split these up among the running guest OS's. This is the partitioning piece. But in the case of, say, network connections, there are generally not enough to go around for each guest to have its own. So we utilize virtualization to allow a small number of limited physical resources to appear as a larger number of virtual resources, allowing each guest to think it has its own private resource (e.g. network connection), when in reality, it's sharing that resource with other guests.

The management software our team develops is just one component of the overall "Logical Domains" (LDoms) technology. Correspondingly, our small team is part of a larger team implementing all the other necessary components to produce the LDoms software "stack".

News first started leaking out about our LDoms effort when David Yen mentioned the technology in an interview he did back in January. More recently, LDoms was announced by John Fowler, the Vice President of the recently formed Systems Group.

Although LDoms has not been released yet, some of the code is already available as part of the OpenSolaris project. In addition, other folks have been blogging about it, so it's time that some of the developers on the LDoms team join in the discussion.

The initial LDoms release will be targeted at our T1000 and T2000 platforms. These systems utilize our UltraSPARC T1 processor and Hypervisor virtualization technology. LDoms leverages the virtualization infrastructure already built in to the hardware and hypervisor of these platforms, and takes it one step further to provide support for dynamically creating & managing multiple logical domains, each able to host its own guest OS. Some customers without highly threaded workloads have asked us how these CMT systems can best work for them. Logical Domains is one important answer.

My role is the team lead for the LDoms Manager software component. The LDoms Manager configures, monitors and controls logical domains, and is itself managed by system administrators (either directly or through other management software). I'll talk more about how the LDoms Manager accomplishes these tasks in subsequent posts. For now, I hope this introduction helps both non-technical and technical folks get a better understanding of what I'm doing in my current project, as well as a little taste of what virtualization technology and our Logical Domains product are all about.

Sunday Oct 01, 2006


Hi! I've been planning to introduce myself to the blogosphere for a while now. I've been tweaking a draft of my initial posting, describing both what I do and what the Logical Domains (LDoms) project I'm involved in is all about, for a couple months now, but the pace of work on our virtualization stack for Sun's SPARC sun4v based platforms (LDoms in eight words) has been preventing me from finishing and posting it.

So why am I posting now? And not at all with what I had initially planned to use to introduce myself? What got me off my duff was Josh Simons' Why Blog? entry. I already understand the benefits of blogging to Sun, its customers, and our own engineering community. But what compelled me to respond was his comment: "...one of you growing up had Howard Stern for a summer camp counsellor". Well, I couldn't just let that comment lie there. Yes, Josh is referring to me.

The year was 1974, the camp was (the now defunct) Wel-Met, and this was no ordinary summer camp experience: Imagine 40 15-16 year old kids, three counselors, and one chartered bus, traveling cross-contry for six weeks, camping out every night. That was the Wel-Met Western Trip. One of those three counselors was a relatively quiet, unassuming guy named Howard Stern (we knew him as Howie). Look here for some photos from our trip.

Okay, enough of that. My goal with this blog is to talk about what we're doing with LDoms, as well my role in the project. I'll tend to stick mostly to technical topics, ranging from a high enough level for my family to understand, to nitty-gritty details only a true geek would enjoy.

I will post my previously planned introductory entry next. But first, thank you Josh, for your none too subtle attempt at goading me into joining the conversation.


I work on the Oracle VM Server for SPARC (nee LDoms) team.

View Eric Sharakan's profile on LinkedIn


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