Hello,
I was wondering if - since defragging is a physical operation which
re-allocates clusters in order to gain performance - running a defrag
from a "virtual" OS makes sense or not, since actually everthing in
the disk is, in the end, a single vhd file.
Consider I have a few VMs (1 .vhd each ) running under Virtual Server,
all hosted on 1 host (1 SAN disk each VM).
I guess defragging the host's disk makes more sense...
Am I missing something?
thanks!

k

Actually the newest versions of DiskKeeper are VM aware and can defragment
internally and externally. I am not aware of any other VM aware (Hyper-V)
defragment utilities.

--
Geoff N. Hiten
Principal SQL Infrastructure Consultant
Microsoft SQL Server MVP




"karamatic" <karamatic@xxxxxx> wrote in message
news:14b581be-5bc8-4d4c-afa4-47ecad4ea69f@xxxxxx

> Hello,
> I was wondering if - since defragging is a physical operation which
> re-allocates clusters in order to gain performance - running a defrag
> from a "virtual" OS makes sense or not, since actually everthing in
> the disk is, in the end, a single vhd file.
> Consider I have a few VMs (1 .vhd each ) running under Virtual Server,
> all hosted on 1 host (1 SAN disk each VM).
> I guess defragging the host's disk makes more sense...
> Am I missing something?
> thanks!
>
> k

On Thu, 12 Feb 2009 15:38:44 -0500, "Geoff N. Hiten"
<SQLCraftsman@xxxxxx> wrote:

>Actually the newest versions of DiskKeeper are VM aware and can defragment
>internally and externally. I am not aware of any other VM aware (Hyper-V)
>defragment utilities.

VM or VHD aware? Makes a big difference.
If a program on the host can break into a virtual machine and do
low-level disk management then we have a no-isolation situation and a
good point for exploits to use.
I thought that a virtual computer was basically totally isolated from
the host with exception of any networking interface....

--

Bo Berglund (Sweden)

It is aware when it is running in a VM environment and adjusts its behavior.

You have to run it inside the VM and in the host to get full advantage. It
does not breack the VM boundary.

--
Geoff N. Hiten
Principal SQL Infrastructure Consultant
Microsoft SQL Server MVP




"Bo Berglund" <boberglund@xxxxxx> wrote in message
news:lb59p4hk2e3uqb8m8mh4m7ukhabgemquto@xxxxxx

> On Thu, 12 Feb 2009 15:38:44 -0500, "Geoff N. Hiten"
> <SQLCraftsman@xxxxxx> wrote:
>

>>Actually the newest versions of DiskKeeper are VM aware and can defragment
>>internally and externally. I am not aware of any other VM aware (Hyper-V)
>>defragment utilities.

>
> VM or VHD aware? Makes a big difference.
> If a program on the host can break into a virtual machine and do
> low-level disk management then we have a no-isolation situation and a
> good point for exploits to use.
> I thought that a virtual computer was basically totally isolated from
> the host with exception of any networking interface....
>
> --
>
> Bo Berglund (Sweden)

On 13 Feb, 05:23, "Geoff N. Hiten" <SQLCrafts...@xxxxxx> wrote:

> It is aware when it is running in a VM environment and adjusts its behavior.
>
> You have to run it inside the VM and in the host to get full advantage. *It
> does not breack the VM boundary.
>
> --
> Geoff N. Hiten
> Principal SQL Infrastructure Consultant
> Microsoft SQL Server MVP
>
> "Bo Berglund" <bobergl...@xxxxxx> wrote in message
>
> news:lb59p4hk2e3uqb8m8mh4m7ukhabgemquto@xxxxxx
>
>
>

> > On Thu, 12 Feb 2009 15:38:44 -0500, "Geoff N. Hiten"
> > <SQLCrafts...@xxxxxx> wrote:

>

> >>Actually the newest versions of DiskKeeper are VM aware and can defragment
> >>internally and externally. *I am not aware of any other VM aware (Hyper-V)
> >>defragment utilities.

>

> > VM or VHD aware? Makes a big difference.
> > If a program on the host can break into a virtual machine and do
> > low-level disk management then we have a no-isolation situation and a
> > good point for exploits to use.
> > I thought that a virtual computer was basically totally isolated from
> > the host with exception of any networking interface....

>

> > --

>

> > Bo Berglund (Sweden)- Nascondi testo citato

>
> - Mostra testo citato -

So, as far as I get it, defragging from inside a VM (sorry, I forgot
to specify my .vhd are alle fixed size ones) is good and improves
performance of the VM itself, BUT you have to use a defrag tool which
is aware of being defragging a VM and not a physical one.
Is this right?
thanks,

k

Correct.

Again, I recommend Diskeeper.

Full Disclosure, I have some free licenses from them for testing. No other
compensation is involved.

--
Geoff N. Hiten
Principal SQL Infrastructure Consultant
Microsoft SQL Server MVP




"karamatic" <karamatic@xxxxxx> wrote in message
news:4712ffd8-088f-4374-8cba-a85ca6930ced@xxxxxx
On 13 Feb, 05:23, "Geoff N. Hiten" <SQLCrafts...@xxxxxx> wrote:

> It is aware when it is running in a VM environment and adjusts its
> behavior.
>
> You have to run it inside the VM and in the host to get full advantage. It
> does not breack the VM boundary.
>
> --
> Geoff N. Hiten
> Principal SQL Infrastructure Consultant
> Microsoft SQL Server MVP
>
> "Bo Berglund" <bobergl...@xxxxxx> wrote in message
>
> news:lb59p4hk2e3uqb8m8mh4m7ukhabgemquto@xxxxxx
>
>
>

> > On Thu, 12 Feb 2009 15:38:44 -0500, "Geoff N. Hiten"
> > <SQLCrafts...@xxxxxx> wrote:

>

> >>Actually the newest versions of DiskKeeper are VM aware and can
> >>defragment
> >>internally and externally. I am not aware of any other VM aware
> >>(Hyper-V)
> >>defragment utilities.

>

> > VM or VHD aware? Makes a big difference.
> > If a program on the host can break into a virtual machine and do
> > low-level disk management then we have a no-isolation situation and a
> > good point for exploits to use.
> > I thought that a virtual computer was basically totally isolated from
> > the host with exception of any networking interface....

>

> > --

>

> > Bo Berglund (Sweden)- Nascondi testo citato

>
> - Mostra testo citato -

So, as far as I get it, defragging from inside a VM (sorry, I forgot
to specify my .vhd are alle fixed size ones) is good and improves
performance of the VM itself, BUT you have to use a defrag tool which
is aware of being defragging a VM and not a physical one.
Is this right?
thanks,

k