When I run CheckDisk on a Windows 8 Consumer Preview volume, I get:

> chkdsk /v S:
The type of the file system is NTFS.
Volume label is Windows 8.

WARNING!  F parameter not specified.
Running CHKDSK in read-only mode.

CHKDSK is verifying files (stage 1 of 3)...
  91392 file records processed.
File verification completed.
  28 large file records processed.
  0 bad file records processed.
  20224 EA records processed.                 <------------------ huh??

Why are there so many extended attributes on the volume? I thought no one used EAs anymore...


As an example, the file \Windows\CSC\v2.0.6 has an extended attribute that contains the string

Ԡ 1X C8A05BC0-3FA8-49E9-8148-61EE14A67687.CSC.DATABASE P X Չ: Չ: ˌΦ]cᑡPcďŠ 4 C8A05BC0-3FA8-49E9-8148-61EE14A67687.CSC.DATABASEEX1 P X _, N0t 08 C8A05BC0-3FA8-49E9-8148-61EE14A67687.CSC.EPOCHEA 8 ͌Φ]cᑡPcďŠ }

which (thanks to an answer below) seems to be related to client-side caching of offline files.

However, it seems like most other EAs are different -- e.g. the file

\Program Files\WindowsApps  

and most other files contains (mostly) the string $KERNEL.PURGE.APPXFICACHE, which doesn't seem to be related. What might this be for?


Based on the EA name "CSC.DATABASE", one might guess it is related to client-side caching. That would also explain why there are so many of them, since each cached file probably has them to identify them with the server.

Also, I don't think EAs are particularly seldom used at all. I know for sure that they are used, for instance, by IE to identify a file as having been "downloaded from the web" (which makes Windows Explorer ask before running the file and such things).

  • 1
    +1 for the client-side caching, I'll take a look to see if that's also the case for other files. However: note that EAs (extended attributes) are not the same as ADSs (alternate data streams)! The latter is used by IE to store the attachment zone information that you mentioned, but EAs, as far as I know, were only for compatibility with other OSes (OS/2?) -- people don't use them much, AFAIK. – user541686 Mar 4 '12 at 8:05
  • I updated the question with another EA -- this one looks different. :) – user541686 Mar 4 '12 at 8:17

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