Wednesday Jun 08, 2011

Oracle VM Server for SPARC 2.1 Released!

I only have time for a quick post this morning, but we're very excited to announce the release of Oracle VM Server for SPARC 2.1. This release contains one of our most requested features: live migration! There will be plenty of folks blogging & describing that feature in detail; in future blog posts I'm going to highlight some of the other lesser-known features of the release.

More to come!

Monday Feb 23, 2009

Oracle 10g certification on Logical Domains

Excellent News! Oracle 10g is now certified & supported on LDoms for both single instances and RAC implementations. The details are available here.

Thursday Nov 01, 2007

Control domain reconfiguration in LDoms 1.0.1

This note explains how control domain reconfiguration works in LDoms 1.0.1, in contrast to how it functioned in LDoms 1.0. There were severe limitations placed on control domain reconfiguration in LDoms 1.0, which have been addressed in the 1.0.1 release:
  • The control domain could only be reconfigured when running in the "factory-default" configuration. Once reconfigured, if subsequent changes were desired, one had to revert back to factory-default and re-apply the initial changes as well as any new ones.
  • The only way to instantiate a newly reconfigured control domain was by downloading the new configuration to the SP, and then power-cycling the box.

When reconfiguring the control domain under LDoms 1.0.1, the LDom Manager enters "delayed reconfiguration" mode the first time it's asked to do something that can't be immediately instantiated (i.e. just about anything other than cpu DR and adding or removing disk volumes). Once in this mode, all subsequent operations are pended in the hypervisor until the control domain reboots. This delayed reconfiguration capability actually existed in LDoms 1.0, but could not be applied to the control domain because rebooting the control domain required a full powercycle of the system to make sure the I/O subsystem was properly reset, causing the loss of any pending operations queued up in the hypervisor.

LDoms 1.0.1 introduces the ability to soft reset the I/O subsystem, allowing the control domain (or any I/O domain) to reboot while the rest of the system stays up. This in turn allows delayed reconfiguration to work on the control domain.

Utilizing delayed reconfiguration mode for control domain reconfiguration also means the reconfiguration can take place at any time, not just when running in the factory-default configuration. This allows the control domain to be reconfigured as many times as needed without having to revert to the factory-default configuration and start over each time.

To facilitate control domain reconfiguration under LDoms 1.0, the LDom Manager ran in a special "config mode" when in the factory-default configuration. In this mode, all reconfiguration requests were simply queued up within the LDom Manager, so that the new config could be downloaded to the SP when ready, and instantiated by power-cycling the box. This mode is still utilized in Ldoms 1.0.1 on UltraSPARC T1 based platforms (when booted into its factory-default configuration). This is to support non-LDoms legacy compatibility mode, since these platforms initially shipped before the advent of LDoms technology. On these systems, the first control domain reconfiguration has to be done the same way it was for 1.0.

All subsequent control domain reconfigurations (and all control domain reconfigurations on T2 based and all future LDoms-supported platforms, as they do not utilize config mode) can be accomplished via delayed reconfig operations followed by a simple reboot of the control domain.

In summary, under LDoms 1.0.1, you can now reconfigure your control domain whenever you want, as many times as you need, without having to revert to factory-default and re-apply all your previous changes, without having to save the configuration to the SP, and without having to power-cycle the box (except for the first-ever reconfiguration on a T1 based platform).

The ability to reboot the control domain without the box power-cycling (aided with some magic I'll leave to Narayan to describe) deserves a little elaboration: it means you can truly reconfigure your control domain even with active guest domains running! The guest domains stay up during the ensuing control domain reboot; VIO services are pended & automatically re-established as the control domain comes back up.

One very important note about saving your domain configuration to the SP: just because you no longer _need_ to save the new configuration to the SP before rebooting the control domain to affect a reconfiguration, doesn't mean you _shouldn't_ save it; you absolutely should! It's _strongly_ recommend to always save any new configuration you create to the SP, otherwise if the system were to lose power, it would revert to a previously saved state (or to factory-default), which is almost certainly _not_ what you want. BTW, you can safely save your configuration even if there are delayed reconfig operations pending; in this case, the configuration that gets saved is the pending one.

Saturday Oct 27, 2007

Leopard upgrade experience

I just upgraded my MacBook Pro laptop to Leopard (aka OS X 10.5). Here are my experiences so far:
  • I ran a full backup first (doesn't everyone?), then performed the default upgrade procedure.
  • On first Leopard boot, Spotlight started re-indexing both my startup drive, and my backup (external FireWire) drive, even though I had previously disabled Spotlight on the external volume. I had to disable it again. I then unmounted the external drive. Spotlight continued to index my internal drive, but starting reporting something ridiculous like -5234923 hours to go. Sure enough, next morning it had still not completed (it said 28% done by then - this is on a 120GB disk with 100GB used). I rebooted, and Spotlight finished indexing in about 10 minutes.
  • My login keychain was messed up. Apparently it didn't like that my keychain had the name of my userid; it insisted on using the keychain named "login", which was empty. Running Keychain First Aid (under the Keychain Access menu) solved the problem, migrating all my keychain data over.
  • 1passwd didn't work initially. Turns out I had an older version installed. When I upgraded to 2.5.0, it started working again. Others are apparently still having problems, see here.
  • X11 is now installed by default. It noticed I had a custom ~/.xinitrc file and warned me about it, asking me what to do (I said to leave it alone). But there are problems. There is now an in /usr/X11/. The Tiger version was in /Applications/Utilities/, and remained there after the upgrade. There also seems to be some detritus left over in /usr: in addition to the directories /usr/X11/ and /usr/X11R6/ (a symlink to /usr/X11/), there is also a /usr/X11R6 1/, which contains its own include, lib & man subdirs.
    When launching X11, I now wind up with _two_ X11 icons in my Dock. One of them blinks for a long time, then shows "Application Not Responding" when ctrl-clicking the dock icon; it can't be killed (though it goes away when I quit the original X11).
    Plus there are two other mysteries: it takes two clicks of the dock icon to switch to an X11 window (and Cmd-Tab to X11 doesn't do the right thing either). Worst of all, three button mouse emulation doesn't work correctly. In Tiger, option-click emulated middle-click and Cmd-click emulated right-click. Now, option-click emulates right-click, and Cmd-click emulates Meta-middle-click. There seems to be no way to emulate a simple middle-click. Since that's how you paste in X11, this is a real problem. This works fine with a real mouse.
  • Mail Act-On & MailTags plugins are both incompatible with Leopard. Actually, Mail Act-On can be re-enabled, look here for details.
  • The Cisco VPN client we use to login to Sun's network works fine under Leopard. This is the first time a major OS X upgrade has not also required a new VPN client. I have heard there are conflicts with the "Back to My Mac" functionality of .Mac, so I went ahead and disabled it as a precaution.
  • no longer breaks long URLs for other mail clients by adding gratuitous spaces. Hallelujah!!
  • iCal now has a preference to set an alarm on new appointments by default. No more need for third party solutions like iCalFix.
  • Quicksilver (web page currently not responding) always displays its icon in the dock, even if I tell it not to. Also, the two items it puts into the system-wide Services menu disappeared for quite some time (including through a couple reboots and rerunning of the Quicksilver setup), but they eventually returned.

    UPDATE 1: An new version of quicksilver which addresses the dock icon issue can be found here.

  • Spaces is great. I was tired of VirtueDesktop's memory leaks & crashing. I just wish it allowed more hotkey options for activating its multi-desktop view (one non-obvious tip: you can set a corner to activate Spaces, but you do it from the Exposé Pref. pane). I also wish I could name the spaces (at least for the menubar pull-down).
  • I haven't played with Time Machine; it looks to be useless for me (and perhaps most laptop users), as it requires a second drive to be attached at all times.
  • UPDATE 2: I can now with confidence state that the AirPort connection/stall problems plaguing me since upgrading to 10.4.10 are completely resolved in Leopard!! This has been a long, frustrating problem for many laptop users since 10.4.10 came out. Although I'm annoyed at Apple for how long they let this drag on, I'm glad it's over for me, and hope they release a fix for those 10.4.10 users not planning to upgrade.
    One interesting change: now when I press the AirPort menubar icon (which is what used to be needed to get the AirPort connection to start up again with this problem in 10.4.10), instead of a delay before anything happens, the menu drops down immediately, with the top line initially saying: "AirPort: Scanning..." for a second or two (in a greyed-out font), before switching to "AirPort: On".
  • UPDATE 3: Salling Clicker stopped working for me; it said Bluetooth wasn't available. There is a preliminary 3.5.1 update available which solved the problem for me.

Tuesday Aug 21, 2007

VIO device renaming by LDom Manager

[This is the first in a series of entries I'll write about tips, tricks & other issues with the LDom Manager.]

The LDom Manager allows you to specify a name for each VIO client & server instance you configure. Currently (i.e. in LDoms 1.0 and the upcoming 1.0.1 releases), this information is not stored as part of the machine description (MD) for the associated guest domain. Instead, the device name to instance mapping is stored in the LDom Manager's private constraints database, which is itself persisted as a simple XML file in the control domain's filesystem.

There are cases where the information in the constraints database doesn't match that of the running system, and in those cases, the LDom Manager, on startup, will apply a canonical name to any VIO device(s) for which no name mapping is available. The two main reasons this can happen are:

  • Loss of the constraints database file (as a result of an OS upgrade, for example)
  • Reverting the system to a configuration stored on the SP containing a different set of VIO devices than the currently running Config.

When the LDom Manager first starts, if it can't find a mapping for a given VIO device in its constraints database, it applies a canonical name using the following heuristics:

For VIO clients: <type><instance #>, where <type> is either "vnet" or "vdisk", and the instance # is incremented for each additional device of type <type> encountered

For VIO servers: <domain-name>-<type><instance #>, where type is "vds", "vsw", or "vcc"

The Ldom Manager's renaming of VIO devices never affects the actual binding of VIO devices to instances in the OS, nor the binding of VIO clients to servers; everything continues to operate normally. The impact is in how the LDom Manager references VIO devices for display and reconfiguration by the user.

There is, however, one more serious problem to note: if a VIO device is configured using a name that matches a potential canonical name, and the LDom Manager subsequently attempts to use that same canonical name on another VIO device, it'll cause the LDom Manager to abort on startup, and eventually enter maintenance mode. This failure can be identified by this message appearing in the LDom Manager's log file:

Assertion failed: 0L != clientp->published_name, file vio_classes.c, line 2471

To work around this, so the LDom Manager can start, its constraints database (stored in /var/opt/SUNWldm/ldom-db.xml) must be hand-edited to rename the offending VIO device to one that doesn't collide with the canonical name namespace. There is a bug open in our bug tracking system for this problem; it's CR #6571091.

We plan to address these issues in an upcoming release (after the 1.0.1 release), by eliminating the need for the LDom Manager to rename VIO devices altogether.

Wednesday Dec 20, 2006

First six weeks with my new MacBook Pro

I've now had my shiny new Intel Core 2 Duo based, 15" MacBook Pro for about six weeks. Here are my impressions, good & bad.

First the bad:

NOTHING. After reading all the reports of various problems with the MacBook Pros, mine has been operating flawlessly. No strange noises, no overheating, no optical drive issues (though I've yet to burn a DVD), no wireless issues.

Okay, one thing: memory. I wish it supported more. I know this isn't Apple's fault, but the 2GB I have is clearly not enough when running Parallels VMs, and I suspect upgrading to the limit of 3GB would only help marginally.

Oh yeah, one more thing: disk speed. The 120GB drive only rotates at 5400RPM, and on I/O bound work, it feels a tad sluggish. The hard drive upgrade option from Apple was even slower, so I stuck with the 120GB.

Now the good:

It's FAST. I'm upgrading from an 867MHz TiBook, and the speed difference is amazing. The migration assistant made the transition painless, and since I'm good about keeping my software up to date, almost everything was already a universal binary and ran at full speed from day one.

One key CPU benchmark for me, SETI@Home, processes each job approximately 5x faster than my TiBook. But with two CPUs, it now processes two jobs at once, for almost a 10x throughput increase!

I opted for the glossy screen, and haven't regretted the decision. This thing is so crisp! I almost never have an issue with glare, and when I do, a very slight adjustment usually resolves that problem.

Other features that are a nice upgrade from the TiBook: built-in Bluetooth & iSight, better WiFi reception, backlit keyboard, and two-finger scrolling. I have to say that this last feature is one of the most productivity-enhancing I've come across in a long time. I now can't stand to sit in front of a laptop who's trackpad desn't support it.

I also splurged for a Bluetooth Mighty Mouse (I already own & love a wired one), and losing the wire is such a pleasure for mousing!

Luckily, Cisco upgraded their VPN client just in time to resolve an issue with the Core 2 Duo chips, so I was able to VPN into Sun's network with no issues.

I love seeing those _two_ CPU load meters in my menu bar, thanks to MenuMeters. At first, I thought it was malfunctioning! Took me a second or two to realize...

There were a couple quirks with X11, but those were quickly resolved with an Update from Apple. I've got Emacs and Open Office working just fine. I haven't been able to get the X11 version of VNC to compile & run sucessfully, so I'm using Chicken of the VNC.

Finally, Parallels rules! I have VMs for Windows XP (Yuck), Ubuntu Linux, and Solaris currently installed. As someone who's currently working on virtualization in my day job (see my posts on LDoms), it's so sweet to have this option on my laptop.

The increasing availability of virtual appliances for Parallels on the web is not only totally cool; it also represents an important evolution for virtualization technology in general. Being able to download, install, configure and run complete software stacks in a matter of minutes really brought home that point to me. It's given me some ideas that I want to see us incorporate into LDoms.

All in all, I'm one very happy customer.

Wednesday Oct 25, 2006

New Macbook Pro

[Caveat: I'm an avid fan of Apple and their Macintosh computers. There are lots of us at Sun. If you don't care to read posts about my experiences with my Macs, then skip anything I write under the "Mac" category.]

I've been waiting for months for Apple to announce Merom (aka Intel Core 2 Duo) processor support in their Macbook Pro laptops. My wait ended last night, and I immediately placed my order:

Product Name: MBPRO 15/2.33 CTO

With the following configuration:
 - Processor	0656642	2.33GHz Intel Core 2 Duo
 - Memory	0656619	2GB 667 DDR2 SDRAM2x1GB
 - Hard Drive	0656623	120GB Serial ATA Drive@5400rpm
 - Optical Drive	0656625	SuperDrive 6X
 - Display	0656632	15 Glossy Widescreen Display
 - Modem	0656645	None
 - Apple Software Solutions	0656200	None
 - Keyboard/Mac OS Language	0656627	BkLit Keyboard/Mac OS
 - Country Kit/AEX	0656628	Country Kit

Estimated Shipped By: OCT 30, 2006
Estimated Delivered By: NOV 06, 2006

This is to replace my four year old, slightly dented but still working, Titanium Powerbook 867MHz workhorse. It's gonna be a long two weeks!


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

View Eric Sharakan's profile on LinkedIn


« April 2014