MPIO - Registry grow

Hi All,

I am writing a MPIO DSM for a new RAID.

The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).

Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,

Gabriel Mizrahi

StoreAge Networking Technologies.

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I am not familiar with MPIO but the registry size limit is something
adjustable by a registry setting, by default a quarter of the size of the
paged pool. This can be changed by setting the RSL value or by changing the
size of the paged pool. On WinXP and 2003 this is not valid anymore and
hives can grow to any size, however I have no idea why registry entries are
not recycled automatically.

/Daniel

“Gabriel Mizrahi” wrote in message
news:xxxxx@ntdev…
Hi All,

I am writing a MPIO DSM for a new RAID.
The problem is that each time I expose a new LUN from the RAID to the Host
were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never removed
from the Registry even if I remove the LUN. If I expose again the same LUN a
new entry is created (the old entry is not replaced). In such case the
Registry grows and can exceed the size limit (in example for Windows 2000
the HKLM\System hive should exceed the 12MB and cause System hive
corruption, black screen and Windows could not load).
Is anyone knows how can I overcome this problem? Can I remove the entries
from the MPIO registry Key? Why MPIO does not remove the entries?

Thanks,
Gabriel Mizrahi
StoreAge Networking Technologies.


This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals & computer
viruses.

The system hive is not set by that parameter. As Gabriel says, it is
fixed in Win2k such that the hive, kernel, boot start drivers and a few
other things all have to fit in 16M.

You have to use SetupDi calls to clean up the registry. The thinking
behind this was to save time on resuse, but as you can see, that doesn’t
really work out. It’s not really an MPIO problem but a PnP design issue.

We also have the scrubber utility available that clears up extraneous
storage entries, BUT… I guess we need to update it to clear out MPIO
entries as well!

-----Original Message-----
From: Daniel Terhell [mailto:xxxxx@resplendence.com]
Sent: Monday, December 12, 2005 1:52 PM
Subject: Re: MPIO - Registry grow

I am not familiar with MPIO but the registry size limit is something
adjustable by a registry setting, by default a quarter of the size of
the paged pool. This can be changed by setting the RSL value or by
changing the size of the paged pool. On WinXP and 2003 this is not valid
anymore and hives can grow to any size, however I have no idea why
registry entries are not recycled automatically.

/Daniel

“Gabriel Mizrahi” wrote in message
news:xxxxx@ntdev…
Hi All,

I am writing a MPIO DSM for a new RAID.
The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).
Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,
Gabriel Mizrahi
StoreAge Networking Technologies.

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This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals &
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viruses.
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*********************

Can I cleanup the section Key of the Enum\MPIO?
If Yes, can I do it from Kernel mode? Which functions should I use?

Gabriel.

-----Original Message-----
Subject: RE: MPIO - Registry grow

From: Jeff Goldner (MS) (xxxxx@microsoft.com)

Date:Mon, 12 Dec 2005 21:10:39 -0800 (quoted)

The system hive is not set by that parameter. As Gabriel says, it is
fixed in Win2k such that the hive, kernel, boot start drivers and a few
other things all have to fit in 16M.

You have to use SetupDi calls to clean up the registry. The thinking
behind this was to save time on resuse, but as you can see, that doesn’t
really work out. It’s not really an MPIO problem but a PnP design issue.

We also have the scrubber utility available that clears up extraneous
storage entries, BUT… I guess we need to update it to clear out MPIO
entries as well!

-----Original Message-----
From: Daniel Terhell [mailto:xxxxx@resplendence.com]
Sent: Monday, December 12, 2005 1:52 PM
Subject: Re: MPIO - Registry grow

I am not familiar with MPIO but the registry size limit is something
adjustable by a registry setting, by default a quarter of the size of
the paged pool. This can be changed by setting the RSL value or by
changing the size of the paged pool. On WinXP and 2003 this is not valid
anymore and hives can grow to any size, however I have no idea why
registry entries are not recycled automatically.

/Daniel

“Gabriel Mizrahi” wrote in message
news:xxxxx@ntdev…
Hi All,

I am writing a MPIO DSM for a new RAID.
The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).
Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,
Gabriel Mizrahi
StoreAge Networking Technologies.

************************************************************************************
This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses.
************************************************************************************

You must create the persistent unique instance ID for a LUN.

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

----- Original Message -----
From: “Gabriel Mizrahi”
To: “Windows System Software Devs Interest List”
Sent: Monday, December 12, 2005 9:17 PM
Subject: [ntdev] MPIO - Registry grow

Hi All,

I am writing a MPIO DSM for a new RAID.

The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).

Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,

Gabriel Mizrahi

StoreAge Networking Technologies.

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Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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The Instance ID for the Multipath LUN is created by the MPIO bus driver
and I am not aware about it.
There is any option to clean the Enum\MPIO registry Key from kernel
mode?
Can I remove these entries whenever the Multipath LUN is removed?

Gabriel.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S.
Shatskih
Sent: Thursday, December 15, 2005 05:16
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] MPIO - Registry grow

You must create the persistent unique instance ID for a LUN.

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

----- Original Message -----
From: “Gabriel Mizrahi”
To: “Windows System Software Devs Interest List”
Sent: Monday, December 12, 2005 9:17 PM
Subject: [ntdev] MPIO - Registry grow

Hi All,

I am writing a MPIO DSM for a new RAID.

The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).

Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,

Gabriel Mizrahi

StoreAge Networking Technologies.




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viruses.
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Questions? First check the Kernel Driver FAQ at
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Questions? First check the Kernel Driver FAQ at
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Yes you can remove these, but no, there is no kernel interface.

-----Original Message-----
From: Gabriel Mizrahi [mailto:xxxxx@storeage.com]
Sent: Thursday, December 15, 2005 1:12 AM
Subject: RE: MPIO - Registry grow

The Instance ID for the Multipath LUN is created by the MPIO bus driver
and I am not aware about it.
There is any option to clean the Enum\MPIO registry Key from kernel
mode?
Can I remove these entries whenever the Multipath LUN is removed?

Gabriel.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S.
Shatskih
Sent: Thursday, December 15, 2005 05:16
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] MPIO - Registry grow

You must create the persistent unique instance ID for a LUN.

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

----- Original Message -----
From: “Gabriel Mizrahi”
To: “Windows System Software Devs Interest List”
Sent: Monday, December 12, 2005 9:17 PM
Subject: [ntdev] MPIO - Registry grow

Hi All,

I am writing a MPIO DSM for a new RAID.

The problem is that each time I expose a new LUN from the RAID to the
Host were the DSM is installed, a new Registry entry is created on
HKLM\System\CurrentControlSet\Enum\MPIO, and those entries are never
removed from the Registry even if I remove the LUN. If I expose again
the same LUN a new entry is created (the old entry is not replaced). In
such case the Registry grows and can exceed the size limit (in example
for Windows 2000 the HKLM\System hive should exceed the 12MB and cause
System hive corruption, black screen and Windows could not load).

Is anyone knows how can I overcome this problem? Can I remove the
entries from the MPIO registry Key? Why MPIO does not remove the
entries?

Thanks,

Gabriel Mizrahi

StoreAge Networking Technologies.




This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals &
computer
viruses.
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**


Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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


Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@storeage.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

IMPORTANT: Do not open attachments from unrecognized senders

******************************************************


The contents of this email and any attachments are confidential.

It is intended for the named recipient(s) only.

If you have received this email in error please notify the system
manager or the

sender immediately and do not disclose the contents to any one or make
copies.

******************************************************


************************************************************


This footnote confirms that this email message has been scanned by

PineApp Mail-SeCure for the presence of malicious code, vandals &
computer viruses.

************************************************************


************************************************************

This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals &
computer viruses.
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************************************************************

This footnote confirms that this email message has been scanned by
PineApp Mail-SeCure for the presence of malicious code, vandals &
computer viruses.
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