December 2008 - Posts
One of the main advantages in virtualization is having the ability to quickly recover
failed systems. By turning a system into a virtual system you are actually turning
it into a file that can be used on any system that has Hyper-V installed on it thus
enabling quick recovery of a failed system.
The main problem is that to be able to backup a VHD file you need to stop the
virtual machine. Now obviously, on mission critical systems you can’t stop a system
every time you want to back it up. To overcome this issues, you can us the Volume
Shadow Service (VSS) mechanism to take a snapshot of the volume that stores
the VHD files and then copy the relevant files to external storage.
Taking a snapshot of a VHD file is possible since Windows 2008 has a built-in Hyper-V
VSS Writer that brings the virtual machine’s hard drive (the VHD file) to a consistent
Once the snapshot is taken, you can manually mount the snapshot and back it up.
To do this, you should use a tool included with Windows 2008 called ‘diskshadow.exe’.
Diskshadow is an interactive interface to VSS. It has a vast list of commands but if we
concentrate on our specific issue you need to issue the following commands:
set context persistent
[You can set it to volatile if you would like to have the snapshot deleted once you exit
the diskshadow.exe application]
add volume <driveletter> alias <alias_you_choose>
(for example add volume t: alias VHDBackup)
set verbose on
Once you complete this set of command you have a snapshot stored.You can view
the stored snapshots by executing the following command:
list shadows all
Once you are ready to back the VHD up, expose the snapshot you would like to use by
using the following command:
expose <ShadowID> <Drive:>
Now you can access the data as you would any drive on your system. To hide the snapshot
execute the following command:
The major advantage of this feature is that you don’t need to stop a virtual machine
to back it up. From my experience the process of taking a snapshot is relatively quick
and it does not tax a system but I would advise that you do it during afterhours.
One more point to consider is disk space,monitor it closely and delete unused snapshots.
This has always bugged me. When using Exchange you have a limit on how many rules
you can create for your mailbox. At first sight you might say,what is the big deal-you almost
never hit the limit. The problem is that once one of your users does actually hit the limit
you have no compelling explanation as to why the limit for Exchange servers up to 2007
was 32KB (http://support.microsoft.com/kb/886616).
In Exchange 2007 this changes, and the limit can be changed to either 64KB, 128KB or
256KB. This can be done by using a cmdlet called set-mailbox.
Set-Mailbox <mailbox> -RulesQuota:<size>
The specific attribute being changed is called appropriately: RulesQuota .
While reading my favorite blogs, I have found the following video that Long Zheng
took at the Microsoft’s visitor center. The video is of a sphere that has information
projected on it (3D).
Lately, we have been messing around with Hyper-V (by saying we,I actually mean
mean myself and the person that won’t tell me his Kazakh name…).
The technology itself is very cool, but as always it has it’s quirks. Oddly enough,
after we ironed out most of the issues a blog post appeared on the ‘Ask the Core
Team’ blog describing the top issues that they have encountered.
The post is very useful (and would have been really great a couple of month ago… :)).
Click here for the post.
Now what does the ‘ds’ stand for?
You might have guessed it: Dual Screen.
Looks like a monster, with a 17” screen you actually get an extension in the form of
a dual screen…
It has been an odd week. First off, it has been a very long time since
I last wrote, and I missed it. I can’t really say what it is about being able to write
without really knowing if someone actually reads it but I do have to admit it’s
Second, it has been a week or rumors in Israel: it seems that someone from a
certain software company, has decided to send an e-mail to all the employees
of that company (actually only to the local branch) saying that a specific snack causes
death in infants. This e-mail spread like fire during dry season to a point that
it has caused the stock of the company that manufactures the snack to drop…
The company turned to the health ministry which issued a communiqué saying that
the snack is perfectly safe…yet the damage has been done,to some extent.
It seems that the company decided not to give up and it might actually sue the panic
For the local media coverage (Hebrew):
The second rumor of the week (ok,of the last month or so) started out as an e-mail
about a pizza parlor, whose owner (and sole operator) is infamous for his
rude behavior toward clients (but he’s pizza is so damn good!!!) that has refused to serve an
autistic child. This e-mail has caused a consumer boycott, creation of Facebook groups
and a few violent reactions towards the owner.
Oddly enough (or maybe not), no one bothered to actually ask the owner what actually
happened. A month after this started, a journalist from Globes decided to publish his
story…and as it turns out that every story has three sides:mine,yours
and the truth. According to the owner, the mother (that started the e-mail) brought
in not one, but three autistic children and told him that she wants him to teach them how to order
pizza. Now considering the fact that this guy is infamous for his “behavior”, and considering
the fact that his pizza parlor is nothing but a shabby “hole in the wall” where he sells
extremely cheap pizza (albeit,very tasty pizza) I think that something stinks here…
The guy is an easy target, he doesn’t have a huge conglomerate behind him to protect him,
he has one broken-down place where he sells good pizza and insults his client(Dr. House style).
You don’t like it,leave.
For the local media coverage:
Now why am I writing about this?
Well,to be honest, because I like the guy’s pizza, I sat there quite a few times and his insults
are always well put and provoked by “there are no stupid questions, only stupid people”. In both
cases mentioned above an irresponsible e-mail has caused catastrophe. In the first case,
since we are dealing with a large company, I am sure that they will survive. In the second case,
on the other hand, this guy may lose his livelihood because someone decided to write something about
him (unless it was a stroke of genius and it was a ploy to draw attention to his place).
In both cases,we as a crowd, accepted these e-mails and never questioned whether it’s content has
any shred of truth in it. The Internet has become a very dangerous and effective weapon. We should
treat the information coming from the Internet with some caution. I love Wikipedia, but is it 100% accurate?
When I run a search about fixing a BitLocker issue am I be sure that a blog post that I find
will not instruct me to kill the data instead of recovering it???
Anyways,one more rumor for this week:
Oddly enough,as I have mentioned in the past, it seems that the tide is turning.
Microsoft, from being perceived as a stagnant giant is currently being looked at
as an innovator by the media.
As an example, take a look at the the following article: