Mark,
The reserved clusters represent the space reserved for possible/pending
writes to compressed files, and space reserved for the USN journal.
Based on the description below, it is probably because you are using
compression. Turn off compression and see if it goes away.
In the compressed file case there are two scenarios to think about. On
the first write after a compressed file is opened NTFS reserves the
space needed to completely uncompress the file. It is done at this
point so if they can’t get the space the write is failed.
The more interesting case is when you memory map a compressed file. As
soon as you map a writeable view the space is reserved to uncompress the
file. Again it is done at this point so you can fail the map request if
there is not enough space. The problem with this scenario is that the
file system can not released the reserved space until it sees a
CLOSE_IRP which can take a long time based on how the system is being
used.
Neal Christiansen
Microsoft File System Filter Group Lead
This posting is provided “AS IS” with no warranties, and confers no
rights
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark K Vallevand
Sent: Friday, February 18, 2005 9:41 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] In the NTFS_VOLUME_DATA_BUFFER, what is TotalReserved?
This is a problem with NTFS on Windows XP embedded edition. I hope
someone
here has an answer. Sorry to barge in. I’m a faithful NT Insider
reader,
and got really stuck on this one. I don’t have much of a reason to look
inside file systems. I mostly do applications, drivers, and XP
embedded.
On my XPe system, the file system is EWF RAM Reg compressed NTFS in
470mb
partition on 512mb Compact Flash. When ASP.NET webpages are accessed,
the
NTFS “Total Reserved” space grows to fill the entire file system.
What are these reserved clusters and why is IIS and ASP.NET using them?
If you stop IIS and delete the ASP.NET temp files (compiled webpages),
the
reserved space is sometimes released. The ASP.NET temp files are quite
small (5mb) and deleting them can free 120mb reserved space. But, this
doesn’t always free the reserved space.
If you commit and restart the machine, the reserved space in the file
system
always is released.
I have tried running with EWF disabled and it behaves the same.
Is this a good forum to ask NTFS questions?
–
Regards.
Mark K Vallevand xxxxx@Unisys.com
Beer is living proof that God loves us and wants us to be happy.
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Questions? First check the IFS FAQ at
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