AW: question about NTFS alternate data streams

NTFSD
1

Neil,

the issues I’m concered about are:

  1. Size restriction (as you already pointed out)
  2. Reparse points (EA’s are reparse points are mutually exclusive)
  3. Support for EAs in the future: Are EAs are a strategic mechanism in ms
    filesystems ?

Besides these 2 topics I think that EA’s are exactly what we need.

Thanks,
Lars

-----Ursprüngliche Nachricht-----
Von: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com]Im Auftrag von Neal
Christiansen
Gesendet: Samstag, 30. Oktober 2004 20:39
An: Windows File Systems Devs Interest List
Betreff: RE: [ntfsd] question about NTFS alternate data streams

Lars,

No, you can not create our own NTFS attribute. That is something
totally internal to the system.

I am wondering why you want to switch to ADS from EAs? If you don’t
need to store a lot of data in the ADS then EAs are more efficient
because it does not require a separate open to access them.

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 Lars Diehl
Sent: Thursday, October 21, 2004 5:23 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] question about NTFS alternate data streams

Hello everybody,

I’ve got a simple question for the NTFS experts about NTFS alternate
datastreams, ntfs attributes and how they can be accessed. I’ve already
checked some old threads in the list and found some controversial
statements. I would like to use ADS to replace EAs in our software.

First, here is my understandig how alternate data streams and ntfs
attributes are adressed.
This is how an NTFS filename looks like:

[path][file.ext]:[ads-name]:[ntfs-attr-name]

Example:
foo.dat:ads1:$DATA

Now the question:
Can I create a new NTFS attribute such as
foo.dat:ads1:LARS
or (using the default data stream)
foo.dat::LARS ?

In my understanding the ntfs-attributes (with some exceptions like
$DATA)
are internal to NTFS, so I should not be able to create my own
ntfs-attributes, right ?
I can create a new data stream (something like “foo.dat:LARS:$DATA”) but
I
would prefer the ntfs attribute solution. (Writing to an alternate data
stream causes the last write time of the to change, which can in fact be
very annoying).

Thanks for any help or comments in advance,

With best regards,
Lars

Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@windows.microsoft.com
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2

Lars,

The Reparse Point issue is a legitimate concern.

We have internal products using EA’s extensively so there are no plans for removing support for them from the NTFS file system.

EA’s are not supported on FAT32 and support may be removed from FAT16 in the future.

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 Lars Diehl
Sent: Sunday, October 31, 2004 5:05 AM
To: Windows File Systems Devs Interest List
Subject: AW: [ntfsd] question about NTFS alternate data streams

Neil,

the issues I’m concered about are:

  1. Size restriction (as you already pointed out) 2. Reparse points (EA’s are reparse points are mutually exclusive) 3. Support for EAs in the future: Are EAs are a strategic mechanism in ms filesystems ?

Besides these 2 topics I think that EA’s are exactly what we need.

Thanks,
Lars

-----Urspr?ngliche Nachricht-----
Von: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com]Im Auftrag von Neal Christiansen
Gesendet: Samstag, 30. Oktober 2004 20:39
An: Windows File Systems Devs Interest List
Betreff: RE: [ntfsd] question about NTFS alternate data streams

Lars,

No, you can not create our own NTFS attribute. That is something totally internal to the system.

I am wondering why you want to switch to ADS from EAs? If you don’t need to store a lot of data in the ADS then EAs are more efficient because it does not require a separate open to access them.

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 Lars Diehl
Sent: Thursday, October 21, 2004 5:23 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] question about NTFS alternate data streams

Hello everybody,

I’ve got a simple question for the NTFS experts about NTFS alternate datastreams, ntfs attributes and how they can be accessed. I’ve already checked some old threads in the list and found some controversial statements. I would like to use ADS to replace EAs in our software.

First, here is my understandig how alternate data streams and ntfs attributes are adressed.
This is how an NTFS filename looks like:

[path][file.ext]:[ads-name]:[ntfs-attr-name]

Example:
foo.dat:ads1:$DATA

Now the question:
Can I create a new NTFS attribute such as foo.dat:ads1:LARS or (using the default data stream) foo.dat::LARS ?

In my understanding the ntfs-attributes (with some exceptions like
$DATA)
are internal to NTFS, so I should not be able to create my own ntfs-attributes, right ?
I can create a new data stream (something like “foo.dat:LARS:$DATA”) but I would prefer the ntfs attribute solution. (Writing to an alternate data stream causes the last write time of the to change, which can in fact be very annoying).

Thanks for any help or comments in advance,

With best regards,
Lars

Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@windows.microsoft.com To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@windows.microsoft.com To unsubscribe send a blank email to xxxxx@lists.osr.com