More virtualization: multiple Win7 guests on a single Debian host

As a proof-of-concept for USC computer science labs, I set up eight Windows 7 VMs on the same physical host in the Windows Server demonstration below, and recorded firing them up simultaneously and doing some light web browsing, etc. on several of them. Performance is pretty solid; you could probably cram double this many guests on that host and still have as good or better performance than the typical physical lab workstation.

update: replaced video with somewhat more watchable version, with all eight guests tiled on one screen.

Aside from good performance and a single box to maintain, this setup offers some fairly compelling advantages over the traditional computer lab: the host also has a 2TB conventional drive in it, which is where a “gold” image of the Win7 guests is maintained. It only takes about 10 minutes total to reset all of the guests to the “gold” standard; and it would be just as easy to keep multiple gold images on the conventional drive for different classes – Linux images for one class, Windows images with Office for a basic class, Windows images with Visual Studio for another, Solaris for yet another… you get the idea.

Also, the time to “reset” the guests could be substantially faster than that, even, with a little tweaking – using .qcow files instead of whole LVM volumes would allow you to use rsync with the –inplace argument and only have to write over the (relatively few) changed blocks, for example; or in a more advanced layout a separate FreeBSD machine with a large RAIDZ array and iSCSI exports could be used to store the images. There’s still plenty of room for improvement and innovation, but even the simple proof-of-concept (which I put together in roughly half an hour) looks pretty compelling to me.

Virtualizing Windows Server with KVM

I’ve been surprised and pleased at just how well Windows Server 2008 runs virtualized under Debian Squeeze. I first started running virtual Windows Servers purely for the disaster recovery and portability aspects, expecting to pay with a drop in performance… but what I found was that in a lot of cases, Windows 2008’s performance is actually somewhat better when running virtually. In particular, the ever-annoying reboot cycle gets cut to a tiny, tiny fraction of what it would be if running on “the bare metal.”

It’s also pretty nice never, ever having to play “hunt-the-driver” – the virtual “hardware” is all natively supported by Windows, so a virtual install “just works” the moment it’s done, no fuss no muss. But what about that performance?

Smokin’! Which exposes yet another reason to think about virtualization: being able to take advantage of Linux’s highly superior kernel RAID capabilities. The box shown above is running four Crucial C300 128GB solid state drives connected to SATA-3 6Gbps ports on an ASUS board; the Debian Squeeze host has them set up in a kernel RAID10. The resulting 250GB or so of storage is on a performance level that just has to be seen to be believed.

Note that while this IS a really “hot” machine, it’s still just one machine, running on commodity hardware – there’s no $50,000 SAN lurking in the background somewhere; that performance is ALL coming from a single machine with a price tag of WELL under $10K.

Ready to upgrade yet? =)

Graphic Equalizer (Treble/Bass) under Linux/Gnome

One of the things that I’ve missed on the Linux desktop is simple audio tone control in the sound volume applet. It particularly annoys me that Gnome allows you to set cruddy little reverb profiles (wow, all my audio sounds like a dog barking now… uh… thanks…), but if your speakers need a little help in the bass or treble department, you’re out of luck. Well, now you’re not!

PulseAudio Multiband Equalizer
the PulseAudio Multiband Equalizer

The PulseAudio System-Wide Equalizer is available from its own Ubuntu PPA, and it is a thing of absolute beauty. I particularly like the fact that the bottom slider is centered at 50Hz – where you want it to add a crisp punch to capable speakers – rather than at the more common 80Hz or even 100Hz, which is more immediately audible but also muddies up the sound rapidly.

Thank you psyke83 for this excellent tool!

Cross-platform Windows Event Log viewer

Another consultant emailed me a .evt file recently for review. Which is great, except I frequently go days now without sitting in front of a Windows workstation – or at least, not one that isn’t broken and in need of fixing. So, I needed to find a Windows Event Log viewer.

There isn’t currently one in the Debian or Ubuntu repositories, but I did find a free-as-in-beer tool at TZWorks, LLC which did the trick nicely. It’s currently available for download in Windows, Linux (i386), and Mac versions – I haven’t tested the Mac version, but the Windows and Linux versions both run fine and do the job well, both for the older .evt and the newer .evtx (Vista and up) formats.

Note: the Linux binary provided is currently 32-bit only, so if you’re running a 64-bit system you’ll either need to install ia32-libs (apt-get install ia32-libs on Debian or Ubuntu), or just run the Windows version under WINE.

EDIT, September 2014: you can’t tell from looking at the download page, but this app now costs $228 for a single copy of it. So, uh, keep moving if you want a reasonable tool to look at Event Viewer logs with, sorry. >=\

B&N Nook Color

So, I finally got an e-reader today. After getting my wife a Nook Color for her birthday, I found it intriguing enough to take the plunge and get my own. I still wasn’t sure I would really be into it, but the only way to find out for sure was to go ahead and take the plunge.

So far, so … well, OK. Some things I really like, others annoy me a lot. The color touchscreen is WORLDS better, for me, than the “e-ink” more typically found in e-readers. The “PC application” is Windows-only… but it does run fine, so far, under WINE in Linux, so there’s that. Battery life seems pretty sweet so far.

One thing that bothers me – the “lending” feature, which was something I heartily approved of, so far seems to require that you link the Nook to your Facebook account… and give it permission to post on your wall. NOT COOL, B&N. I am really, really not okay with applications which can pretend to be you by posting things as though they were you, ever, from pretty much anybody. And to be honest – I am looking at you, Mark Zuckerberg – the fact that this is even an option with Facebook apps drives me insane. There should never be a legitimate case for an application making a post as a human being without that human’s express consent, expressed beforehand, for that particular post. Anyway. Back to the actual device:

The feel of the device in my hands – which was a really big concern for me – is pretty nice so far. Part of how nice it is to hold is the leather “book” cover I got for it, which I am frankly kind of in love with – it’s glossy, nice-smelling black leather, with reverse-embossed classical authors’ names in big all caps serif text all over. I wasn’t sure when I went into B&N today whether I would get the Nook or not – I was really leaning more towards a Samsung Galaxy android tablet. I’m still not sure if I would have actually taken the plunge, without that cover sitting there all seductive-like. Having seen it though… had to have it.

My biggest gripe so far is the interface of the shop. The Nook store is frankly AWFUL – it’s almost impossible to navigate effectively. If you just want to buy whatever is selling well, you’re in luck, and you’ll be very happy. If you have more specific tastes… prepare for some pain. You can search for author name or book title, which is great if you know EXACTLY what you want – and by “great” I mean “OK”, because all you have is a simple, single-level search with no sorting or grouping. Better hope your favorite author has an unusual name, because you can’t limit searches by genre; for example, searching for “David Drake” got me both the military sci-fi author and some young gay dude who wrote a tell-all book. The lack of sorting or grouping is even worse; should you actually find the author you’re looking for, you can expect to find a complete mish-mash of crap: in a series of novels you’ll likely see #5 first, followed by three unrelated books, followed by #7, followed by more unrelateds, followed by #2… you get the idea.

You are also ridiculously likely to see the SAME book multiple times, with a different cover image. It’s even worse in the “free books” section – some dude wrote his own Star Wars book and it’s listed, I kid you not, AT LEAST ten different times. Which wouldn’t be so bad if it was SORTED or grouped in any way, but… did I mention that you can’t sort, or group, and your searches are single-level simple searches only?

Still, so far I’m enjoying the experience of actually *reading* on the device, and with any luck eventually B&N will sort out their godawful navigation issues on the store.