Horrid Disk Read Times in WVPC 2007

We have a WVPC XP VM setup in Windows 7 x64 which is displaying just
horrible read times when accessing one of the local drives of the host.
And I mean *horrible* times!

For example, I can copy a 12MB file from the guest to the host in the
blink of an eye, but copying the same file from the host to the guest
takes several minutes. Even doing a simple DIR at the command prompt
(in a folder with a couple dozen files) shows the sort of noticable
delay you might get doing it in a folder with several thousand files.

This bottleneck is limited to *just* the local drives. There is no
noticable perf problems reading remote/network drives. Mapping the
local drive to a named drive letter does not help. The VM is in
bridged network mode.

Ideas?

--
..NET: It's About Trust!
http://vfred.mvps.org

On 2010-02-19 13:22, Karl E. Peterson wrote:
> We have a WVPC XP VM setup in Windows 7 x64 which is displaying just
> horrible read times when accessing one of the local drives of the host.
> And I mean *horrible* times!
>
> For example, I can copy a 12MB file from the guest to the host in the
> blink of an eye, but copying the same file from the host to the guest
> takes several minutes. Even doing a simple DIR at the command prompt (in
> a folder with a couple dozen files) shows the sort of noticable delay
> you might get doing it in a folder with several thousand files.
>
> This bottleneck is limited to *just* the local drives. There is no
> noticable perf problems reading remote/network drives. Mapping the local
> drive to a named drive letter does not help. The VM is in bridged
> network mode.

I have the same problem on my XP machine. Testing sites on my local
hard drive is very painful, because it is so terribly slow.

The interface between the host and guest is just slow and I suspect
it's a bug.

--
Bob Comer


On Fri, 19 Feb 2010 10:22:45 -0800, Karl E. Peterson <>
wrote:

>We have a WVPC XP VM setup in Windows 7 x64 which is displaying just
>horrible read times when accessing one of the local drives of the host.
> And I mean *horrible* times!
>
>For example, I can copy a 12MB file from the guest to the host in the
>blink of an eye, but copying the same file from the host to the guest
>takes several minutes. Even doing a simple DIR at the command prompt
>(in a folder with a couple dozen files) shows the sort of noticable
>delay you might get doing it in a folder with several thousand files.
>
>This bottleneck is limited to *just* the local drives. There is no
>noticable perf problems reading remote/network drives. Mapping the
>local drive to a named drive letter does not help. The VM is in
>bridged network mode.
>
>Ideas?

Robert Comer wrote:
> The interface between the host and guest is just slow and I suspect
> it's a bug.

I can't say I've seen this on any other VMs, though? I just tried
another, on a different host, and I could sling a 22MB file in moments
from host to guest.

--
..NET: It's About Trust!
http://vfred.mvps.org

>I can't say I've seen this on any other VMs, though? I just tried
>another, on a different host, and I could sling a 22MB file in moments
>from host to guest.

With WVPC? Was VBOX perchance installed also on that box?

It's slow on all my machines, but I don't think every machine behaves
this way. I don't know the cause.

--
Bob Comer




On Fri, 19 Feb 2010 18:11:25 -0800, Karl E. Peterson <>
wrote:

>Robert Comer wrote:
>> The interface between the host and guest is just slow and I suspect
>> it's a bug.
>
>I can't say I've seen this on any other VMs, though? I just tried
>another, on a different host, and I could sling a 22MB file in moments
>from host to guest.

Robert Comer wrote:
>> I can't say I've seen this on any other VMs, though? I just tried
>> another, on a different host, and I could sling a 22MB file in moments
>> from host to guest.
>
> With WVPC?

Yep.

> Was VBOX perchance installed also on that box?

Nope.

> It's slow on all my machines, but I don't think every machine behaves
> this way. I don't know the cause.

It seems highly VM specific, here, so there's gotta be a configuration
issue in play.

--
..NET: It's About Trust!
http://vfred.mvps.org

>It seems highly VM specific, here, so there's gotta be a configuration
>issue in play.

Networking set to NAT vs the physical NIC? I almost always use the
physical NIC.

--
Bob Comer


On Mon, 22 Feb 2010 10:45:49 -0800, Karl E. Peterson <>
wrote:

>Robert Comer wrote:
>>> I can't say I've seen this on any other VMs, though? I just tried
>>> another, on a different host, and I could sling a 22MB file in moments
>>> from host to guest.
>>
>> With WVPC?
>
>Yep.
>
>> Was VBOX perchance installed also on that box?
>
>Nope.
>
>> It's slow on all my machines, but I don't think every machine behaves
>> this way. I don't know the cause.
>
>It seems highly VM specific, here, so there's gotta be a configuration
>issue in play.

Robert Comer wrote:
>> It seems highly VM specific, here, so there's gotta be a configuration
>> issue in play.
>
> Networking set to NAT vs the physical NIC? I almost always use the
> physical NIC.

That might be it, yep! I just tried on another with NIC, and it was
also painfully slow reading a host share.

--
..NET: It's About Trust!
http://vfred.mvps.org

I'll do some testing to when I get a chance, never thought there might
be a difference there...

--
Bob Comer


On Mon, 22 Feb 2010 11:26:40 -0800, Karl E. Peterson <>
wrote:

>Robert Comer wrote:
>>> It seems highly VM specific, here, so there's gotta be a configuration
>>> issue in play.
>>
>> Networking set to NAT vs the physical NIC? I almost always use the
>> physical NIC.
>
>That might be it, yep! I just tried on another with NIC, and it was
>also painfully slow reading a host share.

Robert Comer wrote:
> I'll do some testing to when I get a chance, never thought there might
> be a difference there...

After some more testing here, this (NAT vs NIC) doesn't seem to be the
issue. <sigh>

--
..NET: It's About Trust!
http://vfred.mvps.org