Difference between pages "Mac OS X" and "SuperFetch"

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Apple Inc.'s Macintosh OS X (pronounced "'''OS Ten'''") is the operating system distributed with Apple computers. It includes heavily used several programs by default, including [[Apple Mail]], a web browser called [[Apple Safari | Safari]], and an [[Apple Address Book]], and [[iCal]].  
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SuperFetch is a performance enhancement introduced in [[Microsoft]] [[Windows|Windows Vista]] to reduce the time necessary to launch applications. An expanded version of the [[Prefetch]] files found in Windows XP, they record usage scenarios and load resources into memory before they are needed. Those resources can be loaded into physical memory and extra memory provided by [[ReadyBoost]].
  
== Disk image types ==
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== Configuration ==
  
Mac OS X has support for various disk image types build-in, some of which are:
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Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the <tt>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch</tt> [[Registry]] key [http://www.codinghorror.com/blog/archives/000688.html]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, <tt>services.msc</tt> [http://tiredblogger.wordpress.com/2007/03/27/superfetch-not-so-super-for-gaming/].
* read-write disk image (.dmg) some of which use the [[Raw Image Format]]
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* [[Sparse Image format|Sparse disk image (.spareimage)]]
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* [[Sparse Bundle Image format|Sparse bundle disk image (.sparsebundle)]]
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== Burn Folder ==
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== File Formats ==
  
Mac OS X Burn Folder:
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Data for SuperFetch is gathered by the <tt>%SystemRoot%\System32\Sysmain.dll</tt>, part of the Service Host process, <tt>%SystemRoot%\System32\Svchost.exe</tt>, and stored in a series of files in the <tt>%SystemRoot%\Prefetch</tt> directory [http://www.microsoft.com/technet/technetmag/issues/2007/03/VistaKernel/]. These files appear to start with the prefix <tt>Ag</tt> and have a <tt>.db</tt> extension. The format of these files is not fully known, there is available unofficial partial specification [http://blog.rewolf.pl/blog/?p=214] and open source (GPL) dumper for .db files [http://code.google.com/p/rewolf-superfetch-dumper/]. Some information can be gleaned from these files by searching for [[Unicode]] [[strings]] in them.
<pre>
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$NAME.fpbf
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</pre>
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This folder normally contains [[Mac OS X Alias Files|alias files]] (similar to LNK files under Windows). Which should have the following signature.
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The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [http://channel9.msdn.com/showpost.aspx?postid=242429].
<pre>
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00000000  62 6f 6f 6b 00 00 00 00  6d 61 72 6b 00 00 00 00  |book....mark....|
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</pre>
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These [[Mac OS X Alias Files|alias files]] contain additional date and time values.
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== See Also ==
 
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* [[Prefetch]]
Also check the following files for references to deleted .fpbf paths:
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* [[Windows SuperFetch Format|SuperFetch Format]]
<pre>
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* [[Windows]]
/Users/$USERNAME/Library/Preferences/com.apple.finder.plist
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/Users/$USERNAME/Library/Preferences/com.apple.sidebarlists.plist
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</pre>
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Actual burning of optical media is logged in:
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<pre>
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/var/log/system.log
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/Users/$USERNAME/Library/Logs/DiscRecording.log
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/private/var/.logs_exporter/cache/Users/$USERNAME/Library/Logs/DiscRecording.log
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</pre>
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== HFS/HFS+ date and time values ==
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In HFS+ date and time values are stored in an unsigned 32-bit integer containing the number of seconds since January 1, 1904 at 00:00:00 (midnight) UTC (GMT). This is slightly different from HFS where the date and time value are stored using the local time. The maximum representable date is February 6, 2040 at 06:28:15 UTC (GMT). The date values do not account for leap seconds. They do include a leap day in every year that is evenly divisible by four. This is sufficient given that the range of representable dates does not contain 1900 or 2100, neither of which have leap days. Also see: [http://web.archive.org/web/20090214212148/http://developer.apple.com/technotes/tn/tn1150.html Technical Note TN1150 - HFS Plus Volume Format]
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Converting HFS/HFS+ date and time values with Python:
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<pre>
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import datetime
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print datetime.datetime( 1904, 1, 1 ) + datetime.timedelta( seconds=0xCBDAF25B )
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</pre>
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== Launch Daemons ==
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<pre>
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/Library/LaunchDaemons/
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/System/Library/LaunchDaemons/
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</pre>
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== Quarantine event database ==
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See [http://menial.co.uk/blog/2011/06/16/mac-quarantine-event-database/]
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Snow Leopard and earlier
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<pre>
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/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEvents
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</pre>
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<pre>
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SELECT datetime(LSQuarantineTimeStamp + 978307200, "unixepoch") as LSQuarantineTimeStamp, LSQuarantineAgentName, LSQuarantineOriginURLString, LSQuarantineDataURLString from LSQuarantineEvent;
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</pre>
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Lion and later
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<pre>
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/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEventsV2
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</pre>
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== sleepimage ==
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This file is similar to the hibernation file on Windows.
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<pre>
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/private/var/vm/sleepimage
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</pre>
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Also see: [http://osxdaily.com/2010/10/11/sleepimage-mac/]
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== Package Files (.PKG) ==
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Package Files (.PKG) are XAR archives [http://en.wikipedia.org/wiki/Xar_(archiver)] that contain a cpio archive and metadata [http://s.sudre.free.fr/Stuff/Ivanhoe/FLAT.html].
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== Also see ==
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* [[MacOS Process Monitoring]]
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* [[Acquiring a MacOS System with Target Disk Mode]]
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* [[Converting Binary Plists]]
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* [[FileVault Disk Encryption]]
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* [[File Vault]]
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=== Formats ===
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* [[Basic Security Module (BSM) file format]]
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* [[Property list (plist)]]
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== External Links ==
 
== External Links ==
* [http://www.apple.com/macosx/ Official website]
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* [http://en.wikipedia.org/wiki/Windows_Vista_I/O_technologies#SuperFetch Wikipedia: Windows Vista I/O technologies - SuperFetch]
* [http://en.wikipedia.org/wiki/OS_X Wikipedia entry on OS X]
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* [http://channel9.msdn.com/showpost.aspx?postid=242429 Channel 9 Interview with Michael Fortin of Microsoft on SuperFetch]
* [http://menial.co.uk/blog/2011/06/16/mac-quarantine-event-database/ Quarantine event database]
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* [http://www.informationweek.com/news/showArticle.jhtml?articleID=196902178 Microsoft Predicts The Future With Vista's SuperFetch] from Information Week
* [http://www2.tech.purdue.edu/cit/Courses/cit556/readings/MacForensicsCraiger.pdf Mac Forensics: Mac OS X and the HFS+ File System] by P. Craiger
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* [http://jessekornblum.com/presentations/dodcc08-2.pdf DC3 Presentation: My You Look SuperFetching], by Jesse Kornblum
* [http://web.me.com/driley/iWeb/Previous_files/Directory_Services_Overview.pdf Mac OS X Directory Services Integration including Active Directory]
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* [http://news.softpedia.com/news/SuperFetch-Enhanced-Prefetch-64346.shtml SuperFetch Enhanced Prefetch], by Ionut Ilascu, September 1, 2007
* [http://digitalinvestigation.wordpress.com/2012/04/04/geek-post-nskeyedarchiver-files-what-are-they-and-how-can-i-use-them/ NSKeyedArchiver files – what are they, and how can I use them?]
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* [http://krypted.com/mac-os-x/command-line-alf-on-mac-os-x/ Command Line ALF on Mac OS X]
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* [http://newosxbook.com/DMG.html Demystifying the DMG File Format]
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* [https://code.google.com/p/mac-security-tips/wiki/ALL_THE_TIPS mac-security-tips]
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=== Apple Examiner ===
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* [http://www.appleexaminer.com/ The Apple Examiner]
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* [http://www.appleexaminer.com/MacsAndOS/Analysis/USBOSX/USBOSX.html USB Entries on OS X]
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* [http://www.appleexaminer.com/Downloads/MacForensics.pdf Macintosh Forensics - A Guide for the Forensically Sound Examination of a Macintosh Computer] by Ryan R. Kubasiak
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=== iCloud ===
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== Tools ==
* [http://support.apple.com/kb/HT4865?viewlocale=en_US&locale=en_US iCloud: iCloud security and privacy overview]
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=== Open Source ===
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* [https://code.google.com/p/rewolf-superfetch-dumper/ rewolf-superfetch-dumper]
  
[[Category:Mac OS X]]
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[[Category:Windows]]
[[Category:Operating systems]]
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Revision as of 15:14, 23 April 2014

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Please help to improve this article by expanding it.
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SuperFetch is a performance enhancement introduced in Microsoft Windows Vista to reduce the time necessary to launch applications. An expanded version of the Prefetch files found in Windows XP, they record usage scenarios and load resources into memory before they are needed. Those resources can be loaded into physical memory and extra memory provided by ReadyBoost.

Configuration

Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch Registry key [1]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, services.msc [2].

File Formats

Data for SuperFetch is gathered by the %SystemRoot%\System32\Sysmain.dll, part of the Service Host process, %SystemRoot%\System32\Svchost.exe, and stored in a series of files in the %SystemRoot%\Prefetch directory [3]. These files appear to start with the prefix Ag and have a .db extension. The format of these files is not fully known, there is available unofficial partial specification [4] and open source (GPL) dumper for .db files [5]. Some information can be gleaned from these files by searching for Unicode strings in them.

The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [6].

See Also

External Links

Tools

Open Source