Vista - Defrag fails

I've got a dynamic VHD, current size approx 48GB, max size 64GB. There's
around 25GB of space freed up on the virtual machine. I'd like to shrink the
VHD file down.

With all my other VHDs I run the Dave Whitney defrag program, then
precompact, then inspect/compact the VHD. Works a treat.

With this VHD the defrag gets to around 40% of the first phase (freeing disk
clusters) before grinding to a halt. Worse, on a restart I get constant disk
write errors. Basically the VHD becomes unusable. The VHD file size does not
grow to the max allowed so I can't see why the defrag halts.

Anyone?

Have you ran a chkdsk on it before the defrag, it may already be
corrupt -- or you really might be having the real disk go bad.

--
Bob Comer



On Tue, 16 Sep 2008 11:00:05 +0100, "PM" <pm@xxxxxx_.com.invalid> wrote:

Robert Comer wrote:I've run a Windows defrag on it, which I believe does a chkdsk first, and at
any rate must read pretty much all of the (used area of the) disk anyway.

In between my two defrag attempts, the thing worked perfectly for a couple
of months.

>I've run a Windows defrag on it, which I believe does a chkdsk first, and atThe check that Windows defrag does isn't as thorough as a real chkdsk,
but yes, it should read most of the disk if not all. I'd still do a
chkdsk to see if that's the problem. There may be a bug in the defrag
program I suppose, I don't know as I don't use that one.

--
Bob Comer





On Tue, 16 Sep 2008 12:46:25 +0100, "PM" <pm@xxxxxx_.com.invalid> wrote:

Robert Comer wrote:
I'll run a chkdsk tonight when the machine is less heavily used.

What defragger do you use? I'm led to believe that the Win defrag is no good
as it doesn't pile files up at the beginning of the disk.

>What defragger do you use? I'm led to believe that the Win defrag is no goodI rarely use a defragger, but when I'm compacting a VM disk, I just
use the windows built in one. It doesn't defrag like the old style,
but it does do a decent enough job to consolidate unused space into
chunks that can be compacted out. (The free space can be anywhere for
it to be compacted out)

For real machines, I usually try to have enough space that defragging
is unnecessary.

Maybe someone else here has a better recommendation for a defragger.

--
Bob Comer


On Tue, 16 Sep 2008 14:04:14 +0100, "PM" <pm@xxxxxx_.com.invalid> wrote:

Robert Comer wrote:
Perhaps I'll give the Win defragger a go then.

Unfortunately I've got around 46GB free on the disk, the VHD Compact won't
touch it yet even though a) the compacted file will only be around 25GB and
b) the volume is compressed. Shame it can't be forced to compact.