Device Name Change?

NTFSD
1

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a
Virtual PC.

Can some explain why this is happening and what it means? i.e. does the
volume have more then one device name or does it actually being changed?

Thanks,

Ken

2

Here is another example of a device name changing, this one is from a
physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a
Virtual PC.

Can some explain why this is happening and what it means? i.e. does the
volume have more then one device name or does it actually being changed?

Thanks,

Ken

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:
‘’
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3

What does it mean when you say “the name changes”. Are you saying that
for the same device you query and sometimes get one name and sometimes
get a different name? I’d agree that this doesn’t make much sense, so
I’m wondering if the scenario is different than this.

Tony

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 1:36 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Device Name Change?

Here is another example of a device name changing, this one is from a
physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a
Virtual PC.

Can some explain why this is happening and what it means? i.e. does the
volume have more then one device name or does it actually being changed?

Thanks,

Ken

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: unknown lmsubst tag argument:
‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

4

It happens. Those dynamic volumes have weird properties. I have found that if you run them both through the mount manager you can get the same name back.
“Tony Mason” wrote in message news:xxxxx@ntfsd…
What does it mean when you say “the name changes”. Are you saying that for the same device you query and sometimes get one name and sometimes get a different name? I’d agree that this doesn’t make much sense, so I’m wondering if the scenario is different than this.

Tony

------------------------------------------------------------------------------
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 1:36 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Device Name Change?

Here is another example of a device name changing, this one is from a physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

------------------------------------------------------------------------------

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a Virtual PC.

Can some explain why this is happening and what it means? i.e. does the volume have more then one device name or does it actually being changed?

Thanks,

Ken

—
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: unknown lmsubst tag argument: ‘’
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5

It appears that the mini filter is giving me a different device then the
mount manager.

I query the MOUNT MANAGER for drive letter G and get back:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

I then get a InstanceSetup from the mini filter and call
FltGetVolumeName and get back

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I then query the MOUNT MANAGER with the device name I got from the mini
filter and get:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

Note that the Mount Manager does not ALSO give back this "other" name
when I query by driver letter or by Volume name.

So where does the MINI FILTER get this from? Why are they different?

Which one is the "real" one?

How many other volume names can a volume have?

Thanks,

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Tony Mason
Sent: Thursday, July 13, 2006 1:41 PM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Device Name Change?

What does it mean when you say "the name changes". Are you saying that
for the same device you query and sometimes get one name and sometimes
get a different name? I'd agree that this doesn't make much sense, so
I'm wondering if the scenario is different than this.

Tony

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 1:36 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Device Name Change?

Here is another example of a device name changing, this one is from a
physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a
Virtual PC.

Can some explain why this is happening and what it means? i.e. does the
volume have more then one device name or does it actually being changed?

Thanks,

Ken

Questions? First check the IFS FAQ at

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

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

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''
To unsubscribe send a blank email to xxxxx@lists.osr.com

6

It does give different names. Just accept it and the name you see is not in the mount manager array that gets returned, but if you query it will give you one common name that works to test equality. I guess ftdisk may be involved in the naming, but I don’t know for sure. It makes no difference if the minifilter is used or just an old style file system filter. They both get the bogus names on creates/opens. If you want to eliminate querying for the name each time, you could add it to a table of names. I would make the key the name you get from a mount manager query and then add a link list of ‘other’ names to include volume GUIDs, drive letters (if present), etc.

A better suggestion is to link all the names with bidirectional links to the base name mount manager returns. Then you could link all those symbolic names (create & open seen names) together in sorted order to make binary searching work. However, this is a heavy overhead path, so even mount manager queries shouldn’t be a major slowdown.

P.S. ‘then’ and ‘than’ are different. The first indicates a sequence of two or more things while the second is a comparison. Just a pet peeve of mine.
wrote in message news:xxxxx@ntfsd…
It appears that the mini filter is giving me a different device then the mount manager.

I query the MOUNT MANAGER for drive letter G and get back:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

I then get a InstanceSetup from the mini filter and call FltGetVolumeName and get back

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I then query the MOUNT MANAGER with the device name I got from the mini filter and get:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

Note that the Mount Manager does not ALSO give back this “other” name when I query by driver letter or by Volume name.

So where does the MINI FILTER get this from? Why are they different?

Which one is the “real” one?

How many other volume names can a volume have?

Thanks,

Ken

------------------------------------------------------------------------------

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Tony Mason
Sent: Thursday, July 13, 2006 1:41 PM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Device Name Change?

What does it mean when you say “the name changes”. Are you saying that for the same device you query and sometimes get one name and sometimes get a different name? I’d agree that this doesn’t make much sense, so I’m wondering if the scenario is different than this.

Tony

------------------------------------------------------------------------------

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 1:36 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Device Name Change?

Here is another example of a device name changing, this one is from a physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

------------------------------------------------------------------------------

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a Virtual PC.

Can some explain why this is happening and what it means? i.e. does the volume have more then one device name or does it actually being changed?

Thanks,

Ken

—
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: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
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You are currently subscribed to ntfsd as: unknown lmsubst tag argument: ‘’
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7

\DosDevices\G: is a link to
\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1 and

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1 is a link to
\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

If you use winobj, you will see that
\Device\HarddiskDmVolumes\PhysicalDmVolumes\ also contains RawVolumeX
device objects

It would be interesting to know who (other than LDM!) uses the
RawVolumeX and how it uses it.

LDM inherits it's genes from VxVM.

Harish

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@emc.com
Sent: Thursday, July 13, 2006 2:37 PM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Device Name Change?

It appears that the mini filter is giving me a different device then the
mount manager.

I query the MOUNT MANAGER for drive letter G and get back:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

I then get a InstanceSetup from the mini filter and call
FltGetVolumeName and get back

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I then query the MOUNT MANAGER with the device name I got from the mini
filter and get:

\DosDevices\G:

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

??\Volume{54e5a42b-1de6-4bc4-b631-36c058bcb996}

Note that the Mount Manager does not ALSO give back this "other" name
when I query by driver letter or by Volume name.

So where does the MINI FILTER get this from? Why are they different?

Which one is the "real" one?

How many other volume names can a volume have?

Thanks,

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Tony Mason
Sent: Thursday, July 13, 2006 1:41 PM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Device Name Change?

What does it mean when you say "the name changes". Are you saying that
for the same device you query and sometimes get one name and sometimes
get a different name? I'd agree that this doesn't make much sense, so
I'm wondering if the scenario is different than this.

Tony

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@emc.com
Sent: Thursday, July 13, 2006 1:36 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Device Name Change?

Here is another example of a device name changing, this one is from a
physical machine.

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

WITH

\Device\HarddiskDmVolumes\Lsca4142Dg0\Volume1

Ken

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@emc.com
Sent: Thursday, July 13, 2006 12:30 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Device Name Change?

Have seen where a device name changes from something like this:

\Device\HarddiskDmVolumes\W2kfreeDg0\Volume1

To this:

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolume1

I thought disk volumes names where fixed and did not change.

I am seeing this while running W2K with the mini filter rollup in a
Virtual PC.

Can some explain why this is happening and what it means? i.e. does the
volume have more then one device name or does it actually being changed?

Thanks,

Ken

Questions? First check the IFS FAQ at

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

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

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

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8

>LDM inherits it’s genes from VxVM.

Correct, they are even compatible in on-disk format to some degree I think.

VxVM is now renamed “Veritas Storage Foundation”.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com