"Victoria House [MSFT]" wrote

" wrote in message

Why does defrag increase the disk's "used space"? This happens with both
the
GUI version, and the command-line version. The command line flag "-w"
results in a greater decrease in used space. I used (command line)
defrag c:
-a -v to generate a report, ran the GUI defrag, and then reran a report.
It
seems that the GUI version repeatably increases "used space" by about .7
GB.
The "free space" value sometimes doesn't show a decrease, due to the
lower
precision of the number (no decimal values), and the amount of
fragmentation.
The command line version increased "used space" by 1.37, for each of two
runs that for which I saved the analysis report. The "free space" value
IS
reduced for the more aggressive defrag:
"defrag c: -w -v. Is this additional used space usable, or is it lost
forever, or until the disk is reformatted?

See
http://blogs.technet.com/filecab/arc...g-is-cool.aspx

The blog says that defrag attempts to prevent copy-on-write by the Volume
Shadow copy Service (VSS) where possible.
Whenever this is not possible to prevent, VSS's diff space will increase,
decreasing available free space.

The space is not lost forever, it is being used to back up your files that
have "changed" according to VSS, due to their being moved around by
defrag.
vssadmin.exe will tell you about your shadow storage space. There is a
default maximum allowed shadow storage space (15% of volume), so you
needn't fear your free space decreasing until there's none left.

Thanks for the explanation, Victoria.

--
Rock [MS-MVP User/Shell]

Victoria, I echo Rock's thanks. It is a relief to know that the growth is
limited. I looked at your reference, followed some of the links, and
concluded that the additional space is used for a restore-point in case data
are damaged in the move. Also, thanks for the awareness of other sources of
info. provided by links in the referenced blog. Thanks to everyone who
replied, too.

Mike

"Rock" wrote:

"Victoria House [MSFT]" wrote

" wrote in message

Why does defrag increase the disk's "used space"? This happens with both
the
GUI version, and the command-line version. The command line flag "-w"
results in a greater decrease in used space. I used (command line)
defrag c:
-a -v to generate a report, ran the GUI defrag, and then reran a report.
It
seems that the GUI version repeatably increases "used space" by about .7
GB.
The "free space" value sometimes doesn't show a decrease, due to the
lower
precision of the number (no decimal values), and the amount of
fragmentation.
The command line version increased "used space" by 1.37, for each of two
runs that for which I saved the analysis report. The "free space" value
IS
reduced for the more aggressive defrag:
"defrag c: -w -v. Is this additional used space usable, or is it lost
forever, or until the disk is reformatted?

See
http://blogs.technet.com/filecab/arc...g-is-cool.aspx

The blog says that defrag attempts to prevent copy-on-write by the Volume
Shadow copy Service (VSS) where possible.
Whenever this is not possible to prevent, VSS's diff space will increase,
decreasing available free space.

The space is not lost forever, it is being used to back up your files that
have "changed" according to VSS, due to their being moved around by
defrag.
vssadmin.exe will tell you about your shadow storage space. There is a
default maximum allowed shadow storage space (15% of volume), so you
needn't fear your free space decreasing until there's none left.

Thanks for the explanation, Victoria.

--
Rock [MS-MVP User/Shell]

Sorry, "what" would only be successful?

"mikeyhsd" wrote in message ...
that would only be successful if you disabled the built in Scheduled Task for defrag run.
if you have not disabled it, the it is defragging the xp partition as well.







"DP" wrote in message ...

"Rock" wrote in message
...
" wrote

Another person recently posted this same issue in the vista.general
newsgroup. So now there are two of you who have seen this. Maybe it
occurs across the board, but you are the only ones who have seen it and
posted about it. I haven't seen any replies to his post yet.

I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
no switches in the command). I have wondered about it as well and was hoping
your question would get an answer.

Besides this being a new OS, I'm guessing that 97 percent of users simply
use the GUI defrag, not the command-line defrag. I use the the command line
since I have two disks in three partitions for a total of about 175gb. It
takes a LONG time to defrag all of that.
Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
by using the command-line method.
Since the command-line method involves using the right-click "run as
administrator," that makes the method fairly well hidden to most users.
Hence my estimate that only 3 percent of us use it.
I'll keep monitoring as well.

manually running defrag to prevent defragging your xp drive/partition.
if you still allow the auto Scheduled Task Defrag to run it will still defrag the xp drive.







"DP" wrote in message ...
Sorry, "what" would only be successful?

"mikeyhsd" wrote in message ...
that would only be successful if you disabled the built in Scheduled Task for defrag run.
if you have not disabled it, the it is defragging the xp partition as well.







"DP" wrote in message ...

"Rock" wrote in message
...
" wrote

Another person recently posted this same issue in the vista.general
newsgroup. So now there are two of you who have seen this. Maybe it
occurs across the board, but you are the only ones who have seen it and
posted about it. I haven't seen any replies to his post yet.

I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
no switches in the command). I have wondered about it as well and was hoping
your question would get an answer.

Besides this being a new OS, I'm guessing that 97 percent of users simply
use the GUI defrag, not the command-line defrag. I use the the command line
since I have two disks in three partitions for a total of about 175gb. It
takes a LONG time to defrag all of that.
Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
by using the command-line method.
Since the command-line method involves using the right-click "run as
administrator," that makes the method fairly well hidden to most users.
Hence my estimate that only 3 percent of us use it.
I'll keep monitoring as well.

I don't.
Thanks for the tip, tho.

"mikeyhsd" wrote in message ...
manually running defrag to prevent defragging your xp drive/partition.
if you still allow the auto Scheduled Task Defrag to run it will still defrag the xp drive.







"DP" wrote in message ...
Sorry, "what" would only be successful?

"mikeyhsd" wrote in message ...
that would only be successful if you disabled the built in Scheduled Task for defrag run.
if you have not disabled it, the it is defragging the xp partition as well.







"DP" wrote in message ...

"Rock" wrote in message
...
" wrote

Another person recently posted this same issue in the vista.general
newsgroup. So now there are two of you who have seen this. Maybe it
occurs across the board, but you are the only ones who have seen it and
posted about it. I haven't seen any replies to his post yet.

I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
no switches in the command). I have wondered about it as well and was hoping
your question would get an answer.

Besides this being a new OS, I'm guessing that 97 percent of users simply
use the GUI defrag, not the command-line defrag. I use the the command line
since I have two disks in three partitions for a total of about 175gb. It
takes a LONG time to defrag all of that.
Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
by using the command-line method.
Since the command-line method involves using the right-click "run as
administrator," that makes the method fairly well hidden to most users.
Hence my estimate that only 3 percent of us use it.
I'll keep monitoring as well.

The simple way to recover this lost space is to turn System Restore off and
on again. By the way, when you turn System Restore on in Vista, it does not
automatically create a Restore Point as with XP. You must create a Restore
Point manually - something Microsoft should fix. I just discovered the same
problem as Mike after running defrag c: -r, then defrag c: -w from the
command prompt. I lost 3.6GB the first defrag and then lost another 1.75GB
the second defrag. After turning System Restore off and on, my free space
went from 16% to 41%. This seems like a bug to me - Microsoft, please fix.

HMT

" wrote:

Victoria, I echo Rock's thanks. It is a relief to know that the growth is
limited. I looked at your reference, followed some of the links, and
concluded that the additional space is used for a restore-point in case data
are damaged in the move. Also, thanks for the awareness of other sources of
info. provided by links in the referenced blog. Thanks to everyone who
replied, too.

Mike

"Rock" wrote:

"Victoria House [MSFT]" wrote

" wrote in message

Why does defrag increase the disk's "used space"? This happens with both
the
GUI version, and the command-line version. The command line flag "-w"
results in a greater decrease in used space. I used (command line)
defrag c:
-a -v to generate a report, ran the GUI defrag, and then reran a report.
It
seems that the GUI version repeatably increases "used space" by about .7
GB.
The "free space" value sometimes doesn't show a decrease, due to the
lower
precision of the number (no decimal values), and the amount of
fragmentation.
The command line version increased "used space" by 1.37, for each of two
runs that for which I saved the analysis report. The "free space" value
IS
reduced for the more aggressive defrag:
"defrag c: -w -v. Is this additional used space usable, or is it lost
forever, or until the disk is reformatted?

See
http://blogs.technet.com/filecab/arc...g-is-cool.aspx

The blog says that defrag attempts to prevent copy-on-write by the Volume
Shadow copy Service (VSS) where possible.
Whenever this is not possible to prevent, VSS's diff space will increase,
decreasing available free space.

The space is not lost forever, it is being used to back up your files that
have "changed" according to VSS, due to their being moved around by
defrag.
vssadmin.exe will tell you about your shadow storage space. There is a
default maximum allowed shadow storage space (15% of volume), so you
needn't fear your free space decreasing until there's none left.

Thanks for the explanation, Victoria.

--
Rock [MS-MVP User/Shell]