Disabling the File Access Timestamp
Every time you or an application accesses a file on your computer, the file system
records the date and time the file was accessed and stores the timestamp in two
locations. Simply accessing a file requires the system to write to the master file
table (MFT) and the directory the file is located in, which results in two writes
for every file read. Windows Explorer is one of the most read intensive applica-
tions on your computer. Nothing requires more reads to your file system than
browsing through your files. In Windows 7, Explorer has a number of new file
previews that require even more file reads. All these file reads add up to extra
timestamp writes, resulting in slower performance.
The Microsoft NTFS file system engineers were smart enough to realize that
all this timestamp logging can get out of control very quickly, resulting in an
even greater performance slowdown. Applications usually open only a small
chunk of a file at a time and then repeat the small chunk reads until the entire
file is open. This can generate hundreds and maybe even thousands of file
reads, depending on the file size and application. As you can imagine, many
file reads in a short amount of time can put a lot of extra work on the file sys-
tem. To handle this problem, Microsoft designed NTFS to update only the last
access timestamp about every hour, which breaks down to just one, two-step
timestamp update for each file per hour. This solves the preceding problem but
it still has to do two writes for every file; it just limits the need to update the
same file over and over again.
Disabling the file access timestamp is a great way to speed up Windows
Explorer, but it is not without side effects. Often backup applications utilize the
file access timestamp to determine which files to back up when performing a
sequential backup operation (a backup operation that copies only the files that
have newer timestamps since the last backup date). Check with your backup
application’s web site to find out if it will be affected. If it is, consider doing full
backups instead of sequential backups. Full backups are not affected by the lack
of a last access timestamp.
The process for disabling the file access timestamp is very similar to disabling
MS-DOS filename support. Just follow these steps:
1. Click the Start button, type Command Prompt in the Search box.
2. Command Prompt appears at the top of the list in your Start menu.
Right-click the shortcut and select Run as Administrator.
3. After Command Prompt has loaded in the Administrator context, you can
access the NTFS configuration utility. At the prompt, type fsutil behavior
set disablelastaccess 1.
4. Close Command Prompt and restart your computer for the change to
take effect.
If you run into any problems with this change to your backup application or
any other applications, you can easily undo the tweak. Just type fsutil behavior
set disablelastaccess 0 at the Command Prompt instead.
Every time you or an application accesses a file on your computer, the file system
records the date and time the file was accessed and stores the timestamp in two
locations. Simply accessing a file requires the system to write to the master file
table (MFT) and the directory the file is located in, which results in two writes
for every file read. Windows Explorer is one of the most read intensive applica-
tions on your computer. Nothing requires more reads to your file system than
browsing through your files. In Windows 7, Explorer has a number of new file
previews that require even more file reads. All these file reads add up to extra
timestamp writes, resulting in slower performance.
The Microsoft NTFS file system engineers were smart enough to realize that
all this timestamp logging can get out of control very quickly, resulting in an
even greater performance slowdown. Applications usually open only a small
chunk of a file at a time and then repeat the small chunk reads until the entire
file is open. This can generate hundreds and maybe even thousands of file
reads, depending on the file size and application. As you can imagine, many
file reads in a short amount of time can put a lot of extra work on the file sys-
tem. To handle this problem, Microsoft designed NTFS to update only the last
access timestamp about every hour, which breaks down to just one, two-step
timestamp update for each file per hour. This solves the preceding problem but
it still has to do two writes for every file; it just limits the need to update the
same file over and over again.
Disabling the file access timestamp is a great way to speed up Windows
Explorer, but it is not without side effects. Often backup applications utilize the
file access timestamp to determine which files to back up when performing a
sequential backup operation (a backup operation that copies only the files that
have newer timestamps since the last backup date). Check with your backup
application’s web site to find out if it will be affected. If it is, consider doing full
backups instead of sequential backups. Full backups are not affected by the lack
of a last access timestamp.
The process for disabling the file access timestamp is very similar to disabling
MS-DOS filename support. Just follow these steps:
1. Click the Start button, type Command Prompt in the Search box.
2. Command Prompt appears at the top of the list in your Start menu.
Right-click the shortcut and select Run as Administrator.
3. After Command Prompt has loaded in the Administrator context, you can
access the NTFS configuration utility. At the prompt, type fsutil behavior
set disablelastaccess 1.
4. Close Command Prompt and restart your computer for the change to
take effect.
If you run into any problems with this change to your backup application or
any other applications, you can easily undo the tweak. Just type fsutil behavior
set disablelastaccess 0 at the Command Prompt instead.
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