The concept is correct, the order is backwards. Once you take your 2nd
backup, your first backup is now only a set of block level differences
between the 1st and 2nd. This behavior goes one for subsequent backups.
Backup n is stored in the VHD, backup n-1 is stored as a set of block level
differences (between n and n-1) in a shadow copy. And so on ...
You should typically only have one VHD per volume being backed up. All other
previous backups are saved in terms of shadow copies.
On the web you can get information about VSS in general. There's a TechNet
article coming that will address a lot of the internal behaviors around the
backup features, but this might take over a month. meanwhile you can see
some of it on this presentation:
http://www.microsoft.com/emea/itssho...px?videoid=219
Eduardo
"RichG" <RichG@discussions.microsoft.com> wrote in message
news:567738F2-3C59-405E-9064-FAA6EE7FFE6C@microsoft.com...
> Eduardo:
>
> Thank you very much for the clarification – this makes sense.
>
> If I understand your reply, my second backup is not a COMPLETE system
> backup
> by itself…it is only the difference between my original backup and my
> current
> state.
>
> If so, it would seem to indicate that both of the VHD files (original and
> current) in order to accomplish a complete system restore.
>
> Is this correct?
>
> Is there any documentation on the Microsoft WEB site that fully explains
> this from a technical perspective?
>
> --
> RichG
>
>
> "Eduardo Laureano [MSFT]" wrote:
>
>> Hi Rich,
>>
>> your assumptions are mostly correct. VSS is turned on at the
>> destination where your Complete PC Backups are being saved. At the time
>> you
>> created your 2nd backup, block level data representing your 1st backup
>> was
>> saved to shadow copy. Therefore the space hit that you are seeing.
>>
>> For instance, if you take a 3rd backup, without changing much on your
>> system, you'll see that the space usage should grow only by the amount of
>> changed blocks between the time you took your 2nd and 3rd backups.
>>
>> If you are concerned about the disk space allocation where your backups
>> are
>> being saved, I recommend using Disk Cleanup. From there you can delete
>> all
>> older shadow copies, but the most recent one. Be aware that this means to
>> consequently loose access to older backups.
>>
>> Disk Cleanup -> Files from all users on this computer -> Select volume
>> where
>> backups are being saved -> More Options -> System Restore and Shadow
>> Copies -> Clean up ...
>>
>> Eduardo
>>
>>
>> "RichG" <RichG@discussions.microsoft.com> wrote in message
>> news:6A23BAE1-4554-49AF-8D34-126F3D424EBC@microsoft.com...
>> > My system is configured as follows…
>> >
>> > OS = Windows Vista Business
>> > Internal Disk (drive C) = 120Gb
>> > External Disk (drive H) = 500Gb (USB-connected)
>> >
>> > I ran my first “Complete System backup” of my system on July 11, and
>> > chose
>> > to store the backup files on my external disk (drive H). The backup
>> > completed successfully, and I verified that the system created a 37Gb
>> > VHD
>> > file along with a few other very small files. I then verified that the
>> > amount of free space remaining on my external drive was ~37Gb less than
>> > I
>> > previously had free.
>> >
>> > So far, so good…
>> >
>> > I installed two other software applications on my system (Microsoft
>> > Visio
>> > 2007 and Microsoft Project 2007), and I launched another complete
>> > system
>> > backup this weekend. The backup completed successfully, and I verified
>> > that
>> > the system created a new 25Gb VHD file along with a few other very
>> > small
>> > files.
>> >
>> > I expected to see this new 25Gb VHD file IN ADDITION to the previous
>> > 37Gb
>> > VHD file from the July 11 backup, and was surprised to find that the
>> > previous
>> > 37Gb file appears to be MISSING. At least, I cannot find the file in
>> > the
>> > folder where it previously existed.
>> >
>> > I checked the free space on my external H drive, and found that I have
>> > ~
>> > 25Gb less free space than I had before. It is as if the 37Gb file is
>> > still
>> > on the drive somewhere, but I cannot find it. When I launch the backup
>> > program, it states that the last complete backup was run this weekend,
>> > and
>> > it
>> > also seems to indicate that a previous backup does exist, but it does
>> > not
>> > list it my name or date.
>> >
>> > I see from the documentation that a complete system backup will run so
>> > long
>> > as enough free space exists, and that it will automatically delete
>> > older
>> > backups (oldest first) as necessary to insure that free space is
>> > available.
>> >
>> > I use this external drive to store other information in addition to
>> > complete
>> > system backups, and I need to insure that I always have enough free
>> > space
>> > to
>> > handle my needs. My plan was to run a complete system backup whenever
>> > my
>> > system configuration changes significantly, or every month or so –
>> > whichever
>> > comes first. I planned on keeping perhaps 3-4 complete system backups
>> > on
>> > my
>> > external drive, and to delete the older backups as necessary.
>> >
>> > NOTE: I am generally aware of volume shadow copy and how it can reduce
>> > the
>> > amount of free space on a volume, but I’m not sure if this is
>> > compounding
>> > my
>> > issue or not.
>> >
>> > QUESTION:
>> >
>> > Can anyone tell me (or does documentation exist that explains) how to
>> > manage
>> > complete system backup files? How does one manage these backups?
>> >
>> > Any assistance is appreciated...
>> >
>> > --
>> > RichG
>>