Hi,
I have to write an offline storage manager driver for Windows. What the
driver needs to do is to report to Windows that a file exists and has a
certain size even if the file is stored in offline storage. When the
file is requested, I would also need to access the offline storage
device directly and then pass the bytes back up to Windows.
I have a few questions before I start on this project:
- What should I be writing to do this – A filter driver? A
minifilter?
- Can I use the new driver framework? KMDF? UMDF?
- Is there a specific sample in the WDK that is really close to
what I need?
- Does the driver need to be in kernel mode? User mode?
- Is it possible to check if a file is about to be changed? I
would like to also implement “copy on write” and make a backup copy of a
file before it actually changes.
Thanks in advance!
Chris
“Yourch, Chris” wrote in message news:xxxxx@ntfsd…
1. What should I be writing to do this – A filter driver? A
minifilter?
Use a mini-filter there is little justification in using a legacy filter at
the point.
2. Can I use the new driver framework? KMDF? UMDF?
No, the frameworks are not for file system work.
3. Is there a specific sample in the WDK that is really close to
what I need?
No.
4. Does the driver need to be in kernel mode? User mode?
Kernel mode.
5. Is it possible to check if a file is about to be changed? I
would like to also implement “copy on write” and make a backup copy of a
file before it actually changes.
Depends on the level of accuracy you want in “knowing it will be changed”
and the amount of work you want to implement the copy on write.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
Thanks for the help!
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Don Burn
Sent: Thursday, May 03, 2007 5:25 AM
To: Windows File Systems Devs Interest List
Subject: Re:[ntfsd] where should this newbie start?
“Yourch, Chris” wrote in message
news:xxxxx@ntfsd…
1. What should I be writing to do this – A filter driver? A
minifilter?
Use a mini-filter there is little justification in using a legacy filter
at
the point.
2. Can I use the new driver framework? KMDF? UMDF?
No, the frameworks are not for file system work.
3. Is there a specific sample in the WDK that is really close to
what I need?
No.
4. Does the driver need to be in kernel mode? User mode?
Kernel mode.
5. Is it possible to check if a file is about to be changed? I
would like to also implement “copy on write” and make a backup copy of a
file before it actually changes.
Depends on the level of accuracy you want in “knowing it will be
changed”
and the amount of work you want to implement the copy on write.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@replicus.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
One question, what kind of effort am I looking at here? My manager is
eager to know what we are getting into.
Again, I am writing an offline storage manager driver for Windows. Kind
of like the HSM from Microsoft. What the driver needs to do is to report
to Windows that a file exists and has a certain size even if the file is
stored in offline storage. When the file is requested, I would also need
to access the offline storage device directly and then pass the bytes
back up to Windows.
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Don Burn
Sent: Thursday, May 03, 2007 5:25 AM
To: Windows File Systems Devs Interest List
Subject: Re:[ntfsd] where should this newbie start?
“Yourch, Chris” wrote in message
news:xxxxx@ntfsd…
1. What should I be writing to do this – A filter driver? A
minifilter?
Use a mini-filter there is little justification in using a legacy filter
at
the point.
2. Can I use the new driver framework? KMDF? UMDF?
No, the frameworks are not for file system work.
3. Is there a specific sample in the WDK that is really close to
what I need?
No.
4. Does the driver need to be in kernel mode? User mode?
Kernel mode.
5. Is it possible to check if a file is about to be changed? I
would like to also implement “copy on write” and make a backup copy of a
file before it actually changes.
Depends on the level of accuracy you want in “knowing it will be
changed”
and the amount of work you want to implement the copy on write.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@replicus.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Getting it to report the original file size after you have moved the data offline is the easy part, at least on NTFS volumes. Take a look at sparse file support. Implementing the rest of it is variable, depending on how feature rich you need to make it (relative to the other HSM solutions available). For something basic I would guesstimate 6 to 9 months, more if you have no experience at all with filter drivers.
I would guess 18 to 24 months to have a production quality product. This
is in part since you are a newbie, I suspect OSR could deliver it quicker
even with the work backlog that they normally maintain.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
“Yourch, Chris” wrote in message news:xxxxx@ntfsd…
One question, what kind of effort am I looking at here? My manager is
eager to know what we are getting into.
Again, I am writing an offline storage manager driver for Windows. Kind
of like the HSM from Microsoft. What the driver needs to do is to report
to Windows that a file exists and has a certain size even if the file is
stored in offline storage. When the file is requested, I would also need
to access the offline storage device directly and then pass the bytes
back up to Windows.
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Don Burn
Sent: Thursday, May 03, 2007 5:25 AM
To: Windows File Systems Devs Interest List
Subject: Re:[ntfsd] where should this newbie start?
“Yourch, Chris” wrote in message
news:xxxxx@ntfsd…
1. What should I be writing to do this – A filter driver? A
minifilter?
Use a mini-filter there is little justification in using a legacy filter
at
the point.
2. Can I use the new driver framework? KMDF? UMDF?
No, the frameworks are not for file system work.
3. Is there a specific sample in the WDK that is really close to
what I need?
No.
4. Does the driver need to be in kernel mode? User mode?
Kernel mode.
5. Is it possible to check if a file is about to be changed? I
would like to also implement “copy on write” and make a backup copy of a
file before it actually changes.
Depends on the level of accuracy you want in “knowing it will be
changed”
and the amount of work you want to implement the copy on write.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@replicus.com
To unsubscribe send a blank email to xxxxx@lists.osr.com