Windows reports file sizes two different ways

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	LANGALIST PLUS Windows reports file sizes two different ways
	By Fred Langa The amount of space a file occupies on your hard drive is different from — and almost always larger than — the actual/reported size of the file. You have to allow for the difference when sizing a new hard drive.

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Some feedback on your exposure of my USB driver problem. The last entry in your response led to the answer which was applied in a couple of minutes – marvelous. It has saved me from doing a Repair Install which I was not looking forward to.

The solution involved deleting the Lower Filter Registry entry after backing up the Registry and using RegEdit. I also had to find out the GUID of the scanner and image devices. All the instructions for this fix were at the following URL:

http://pcsupport.about.com/od/findbyerrormessage/a/code-39-error.htm

So, I am back in business with a working scanner and webcam and the heart palpitations have also stopped (slight exaggeration). Anyway, in less than 10 minutes the modest cost of the paid version of Windows Secrets was completely justified and also confirmed that this is just about the best on-line resource for the home serviceman.

Thanks a Bunch as I believe you say in that part of the hemisphere.

Peter R Jensen in Sydney, Australia

PS I also asked about an assertion by one of your writers, now gone elsewhere, that a Windows update had removed the capacity to do a Repair Install. Is this correct or has Microsoft replaced this capability in later updates of Windows XP SP3?

PRJ

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To further complicate matters, short files content is stored in the MFT table entry for the file instead of a separate cluster (typically under about 900 bytes per Microsoft or 700-800 per Wikipedia).

From http://technet.microsoft.com/en-us/library/cc781134(v=ws.10).aspx#w2k3tr_ntfs_how_dhao:
NTFS creates a file record for each file and a folder record for each folder created on an NTFS volume. The MFT includes a separate file record for the MFT itself. These file and folder records are 1 KB each and are stored in the MFT. The attributes of the file are written to the allocated space in the MFT. Besides file attributes, each file record contains information about the position of the file record in the MFT. The figure MFT Entry with Resident Record shows the contents of an MFT record for a small file or folder. Small files and folders (typically, 900 bytes or smaller) are entirely contained within the file’s MFT record.
MFT Entry with Resident Record
———————————————————————————
| Standard information | File or Directory name | Data or Index | Unused Space |
———————————————————————————

From http://en.wikipedia.org/wiki/NTFS#Metafiles section titled “Resident vs. non-resident data streams”:

When the stream data can be accessed directly from within the stream descriptor, it is called “resident data”… The amount of data which fits is highly dependent on the file’s characteristics, but 700 to 800 bytes is common in single-stream files with non-lengthy filenames and no ACLs.

Since resident files do not directly occupy clusters (“allocation units”), it is possible for an NTFS volume to contain more files on a volume than there are clusters. For example, a 74.5 GB partition NTFS formats with 19,543,064 clusters of 4 KB. Subtracting system files (a 64 MB log file, a 2,442,888-byte Bitmap file, and about 25 clusters of fixed overhead) leaves 19,526,158 clusters free for files and indices. Since there are four MFT records per cluster, this volume theoretically could hold almost 4 × 19,526,158 = 78,104,632 resident files.

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Do these extra Resident Files affect reporting of available or used disk space? If not, this entire technical discussion is irrelevant to the letter.

-- rc primak

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Sorry to see things go into messed up for a while unitl the powers that be get the Columb into a format they can live with, Last Week we could not vote on half the Writers, this week we don’t even have but a few writers

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Sorry to see things go into messed up for a while unitl the powers that be get the Columb into a format they can live with, Last Week we could not vote on half the Writers, this week we don’t even have but a few writers

Yeah, I miss the direct links from the columns to The Lounge. I thought maybe it was my browser, but I guess not. Also, I had to update my Reader Information and I still got only the invite to see the free content this week. These matters and all related issues should be taken to the Lounge Forum Feedback and Announcements area, or else use the Windows Secrets Contact Form to report issues like these.

-- rc primak

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The best way to contact the Newsletter administration is to use the Contact link on the link bar at the top of the main Lounge page. This is the contact link that allows you to send a message related to the Newsletter. The Contact Us link at the bottom of the Lounge page is only for reporting Log in difficulties and adminstration issues involving the Lounge Forums, and does not include the Newsletter.

The Lounge Feedback and Announcements Forum is not recommended for posting Newsletter issues and problems – only Lounge issues.

I hope this makes clear the proper reporting channels for expedited communications.

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Thank you.

-- rc primak

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