Volume upper filter, volsnap load order question

NTDEV
1

Hi
I have a question regarding load order of volume class uppper filters and volsnap on Windows 2003 servers.

Our product has one volume class upperfilter driver. After installing, from device object stack , I see that our Volume class Upper filter driver is layred above volnap. Before installing our filter driver, I checked that there is no upperfilter key present.
Whereas on Winodws XP test systems I see, explicit UpperFilters entry for Volsnap under
HKLM\System\CurrentControlSet\Control\Class{71A27…}. But I do not see such entry on my Windows 2003 Server systems.

My question is -

  1. Does it mean that on Windows 2003 Server, volsnap is always loaded before any volume class upper filter driver(s) are loaded?

thanks

  • dhanesh
2

> 1. Does it mean that on Windows 2003 Server, volsnap is always loaded before

any volume class upper filter driver(s) are loaded?

On 2003, VolSnap is the FDO for the Volume class.

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

3

So in my upper volume filter, can I assume that I will get
IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES if someone(user land!) sends it.
Is there a possibility that if someone sends this ioctl, my driver will
not see it.
I am assuming that this ioctl is destined for volsnap.

Harish

4

Yes, it is destined for VolSnap with some handling (cache flush) in the
FSD.

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

“Harish Arora” wrote in message news:xxxxx@ntdev…
So in my upper volume filter, can I assume that I will get
IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES if someone(user land!) sends it.
Is there a possibility that if someone sends this ioctl, my driver will
not see it.
I am assuming that this ioctl is destined for volsnap.

Harish