[side note: Windows Vista, and Windows Server 2008 use v6.0 of the windows kernel.
Windows 7 uses v6.1 of the kernel. They’ve also upgraded Windows Server 2008 to use
v6.1 – and called this refresh Windows Server 2008 R2… but they’ve called the client
refresh Windows 7. Even though it technically is just Vista refreshed with an updated
kernel.
I suspect that MS got so burnt with the Vista brand name, that they’ve been forced
to re-name it.
But I wonder what the client OS which will contain v7.0 of the kernel will be called.
I suspect it won’t be Windows 8!]
So Windows 7 is pretty much Windows Vista with some new features.
And some of them are pretty cool (e.g. reduced resource footprint, improvements in
collaborating with connected computers/devices). But don’t be fooled into thinking
that this is a new OS, or even an evolution – it’s Vista with some new features.
Which is absolutely fine – Microsoft have just managed to stabilize Vista, and are
starting to leave the early painful years behind.
For me, the coolest and most useful feature is the ability to boot from a VHD.
Now just stop and think about what that means: there must be a thin layer of bootstrap
code which knows how to read a VHD and present to as a physical HDD/Storage Controller
to the system.
[Note: yes, Win 7 allows you to create/mount VHDs using DiskManager, but this functionality
has been around for a while if you installed Virtual Server, although it was command-line
only.]
I imagine this bootstrap code is pretty much the same as for Windows Hyper-V server,
which works on a similar principle i.e. booting from images, although Hyper-V does
this in a virtualised environment, allowing you to boot multiple VHDs at the same
time.
What I’m not clear about is if the VHD must contain an install of Win 7, or whether
you can boot any OS install. If the latter, then this is super cool.
(given that there appears to be a VHD HostBusAdapter in Device Manager in Win 7, I
suspect it’s the former i.e. Win 7 only VHDs. I hope not.)
What this means for me: I do all of my BizTalk/Services dev in Windows Server 2003/2008.
And up to now, this has been done using Virtual PC images (running Vista 64-bit as
the host OS).
But now, hopefully, I have the choice of booting my dev VHD, or running it in VPC/Virtual
Server/Hyper-V.
And that’s pretty cool.