Copying NTFS Hard Links and Junctions to and from CD/DVD

  • Thread starter Thread starter Kevin Myers
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Kevin Myers

Hello,

We have a very large set of directories and files on hard disk under Windows
2000 that we need to copy to CD or DVD. However, within this set of
directories, NTFS hard links and junctions (reparse points) are used to
provide alternate paths to the same files and folders (essentially
supporting an object-relational navigation structure within the file
system), and we need to duplicate those alternate paths on the CD or DVD.

The CD/DVD burning applications that I have tried all appear oblivious to
hard links and junctions, blindly following all paths through to their
lowest levels, and creating multiple copies of my files as a result. That
is unacceptable because the tremendous number of duplicate files that are
produced *greatly* expands the volume of data that needs to be recorded,
exceding the capacity of the media. Also, this situation makes it
impossible to re-create the original structure when copying from the CD or
DVD back to the hard drive.

Whereever possible, normal Windows shortcuts are used for our application,
and those don't cause any problems. However, shortcuts aren't an acceptable
substitute in the situations where we use NTFS hard links and junctions.
Among other reasons, Windows doesn't support searching through a shortcut to
the linked file or folder, while this works fine with hard links and
junctions, and that is a critical need for us.

I know that the Rock Ridge extensions to the ISO9660 CD file system support
both hard links and symbolic links. For our purposes, either one would be
an acceptable substitute for the NTFS hard links and junctions that we are
using, although hard links would be a more directly equivalent
representation.

1. Does anyone know how it would be possible and what software could be used
to replicate our file and directory structure onto CD or DVD, *including*
actual hard links in the CD file system as substitutes for our NTFS hard
links and junctions?

2. Conversely, if the desired file and directory structure including hard
links can be created on CD/DVD, then does anyone know how it would be
possible and what software would be required to replicate this structure
back onto hard disk, substituting NTFS hard links and junctions where
required?

Thanks greatly in advance for any help.

s/KAM
 
Hello Kevin,

Have you considered backup the files up using NTBackup to a file on the hard drive and then burning the backup to the CD or DVD drive?

Joe Griffin [MS]
Windows 2000 Server Setup Team
 
Hi Joe,

Thanks for your suggestion. Yes, after posting my original message in this
thread yesterday, I did using backup/restore as one possible work-around.
However, the disadvantage to that approach is that the files can't be used
directly from the CD or DVD, and they would have to be restored from the
backup to hard disk prior to use. While not necessarily an absolute killer,
that is a *very* significant problem. Let me explain why...

The directory structure in question which includes hard links and junctions
that we would like to copy to CD is a structure that we use when building
and gathering supporting data for complex projects that we propose. This
structure makes it easy to navigate between documents that are related to
different business objects that are addressed and used as supporting
evidence for our proposals. It allows one to easily navigate between
documents for business objects that are related to each other in multiple
ways, e.g. geographical, organizational, transactional, or through
regulatory ties.

Once we have finished gathering and preparing all of the necessary documents
and data for our proposals (these are *far* from simple Word documents and
the like), we need to provide all of our data to our prospective clients for
their own review and in-house evaluation on their machines. We would like
to deliver the data on CD or DVD for this purpose. From several
standpoints, it is very undesirable to need to copy (or even worse
*restore*) our data onto the customer's machine:

1. It could result in confidentiality breaches if the data gets left on the
customer's machine beyond their evaluation period, and someone else comes
along and finds the data on their machine.
2. The customer might not have enough free space readily available to
restore our rather large directory structures and files to their hard
drives, or enough patience to wait for the restore to complete.
3. The customer may be very unfamiliar and uncomfortable with using the
restore process.

All in all, it would just plain be a whole lot better if the customer could
directly access our data on the CD or DVD itself, rather than being forced
to copy it to their hard drives. So, we need the ability to create the
identical file structure and behavior on the CD or DVD that we have on our
own NTFS formatted hard drives, specifically including the hard links and
junctions. That way, our clients will be able to navigate and search the
data just like we do, with no need to copy our data onto their machines.

Make sense?

s/KAM


Joe Griffin said:
Hello Kevin,

Have you considered backup the files up using NTBackup to a file on the
Click to expand...
hard drive and then burning the backup to the CD or DVD drive?
Joe Griffin [MS]
Windows 2000 Server Setup Team
Click to expand...
 
Hello,

We have a very large set of directories and files on hard disk under
Windows 2000 that we need to copy to CD or DVD. However, within this
set of directories, NTFS hard links and junctions (reparse points) are
used to provide alternate paths to the same files and folders
(essentially supporting an object-relational navigation structure
within the file system), and we need to duplicate those alternate
paths on the CD or DVD.

The CD/DVD burning applications that I have tried all appear oblivious
to hard links and junctions, blindly following all paths through to
their lowest levels, and creating multiple copies of my files as a
result. That is unacceptable because the tremendous number of
duplicate files that are produced *greatly* expands the volume of data
that needs to be recorded, exceding the capacity of the media. Also,
this situation makes it impossible to re-create the original structure
when copying from the CD or DVD back to the hard drive.

Whereever possible, normal Windows shortcuts are used for our
application, and those don't cause any problems. However, shortcuts
aren't an acceptable substitute in the situations where we use NTFS
hard links and junctions. Among other reasons, Windows doesn't support
searching through a shortcut to the linked file or folder, while this
works fine with hard links and junctions, and that is a critical need
for us.

I know that the Rock Ridge extensions to the ISO9660 CD file system
support both hard links and symbolic links. For our purposes, either
one would be an acceptable substitute for the NTFS hard links and
junctions that we are using, although hard links would be a more
directly equivalent representation.

1. Does anyone know how it would be possible and what software could
be used to replicate our file and directory structure onto CD or DVD,
*including* actual hard links in the CD file system as substitutes for
our NTFS hard links and junctions?

2. Conversely, if the desired file and directory structure including
hard links can be created on CD/DVD, then does anyone know how it
would be possible and what software would be required to replicate
this structure back onto hard disk, substituting NTFS hard links and
junctions where required?

Thanks greatly in advance for any help.

s/KAM
Click to expand...

Problem is Rock Ridge is UNIX only. I don't know of anything for Windows
that supports junction points on CD/DVD. Since it would have to include
both file system extensions and burning support I doubt anyone has done
that on their own.

Joe had mentioned using a backup program. The only other type of program
I can think of is something like Winrar or Zip file. However I don't
know of any programs that support junction points but that should be
possible to do.

Leonard Severt

Windows 2000 Server Setup Team
 
Hi Leonard,

Thanks for your reply.

1. I know that many folks have asked for better Windows support of both hard
links and symbolic links so that similar capabilities to those used for many
worthwhile purposes in the *nix world would be available in Windows. Do you
know if additional hard link and/or symbolic link support is planned for any
Windows release in the forseeable future?

2. Given the fact that NTFS already supports hard links and junctions, don't
you think that is reasonable to expect the ability to create a file system
on CD/DVD that can support those same capabilities, so that application
files can be used transparently from CD/DVD just like they can from a hard
drive?

3. I am not an expert on CD file systems. But, while the Rock Ridge
extensions may have been originated for *nix support, I don't see any reason
that they couldn't be supported by Windows and Windows CD/DVD burning
applications. After all, *no* existing CD file system is truly an exact
replica of any native OS hard disk file system. Therefore, *any* current
CD/DVD file system requires a certain level of custom support in the OS.
So, why not just add Windows support for the ISO9660 Rock Ridge extensions
accordingly? It would just be another installable file system, or perhaps a
relatively minor modification or extension to one of the existing CD/DVD
file systems that you already support, right?

s/KAM
 
Hi Leonard,

Thanks for your reply.

1. I know that many folks have asked for better Windows support of
both hard links and symbolic links so that similar capabilities to
those used for many worthwhile purposes in the *nix world would be
available in Windows. Do you know if additional hard link and/or
symbolic link support is planned for any Windows release in the
forseeable future?

2. Given the fact that NTFS already supports hard links and junctions,
don't you think that is reasonable to expect the ability to create a
file system on CD/DVD that can support those same capabilities, so
that application files can be used transparently from CD/DVD just like
they can from a hard drive?

3. I am not an expert on CD file systems. But, while the Rock Ridge
extensions may have been originated for *nix support, I don't see any
reason that they couldn't be supported by Windows and Windows CD/DVD
burning applications. After all, *no* existing CD file system is
truly an exact replica of any native OS hard disk file system.
Therefore, *any* current CD/DVD file system requires a certain level
of custom support in the OS. So, why not just add Windows support for
the ISO9660 Rock Ridge extensions accordingly? It would just be
another installable file system, or perhaps a relatively minor
modification or extension to one of the existing CD/DVD file systems
that you already support, right?

s/KAM


Leonard Severt said:
Problem is Rock Ridge is UNIX only. I don't know of anything for
Windows that supports junction points on CD/DVD. Since it would have
to include both file system extensions and burning support I doubt
anyone has done that on their own.

Joe had mentioned using a backup program. The only other type of
program I can think of is something like Winrar or Zip file. However
I don't know of any programs that support junction points but that
should be possible to do.

Leonard Severt

Windows 2000 Server Setup Team
Click to expand...

Your points are well thought out. However I don't know of any plans for
any major changes to NTFS support for hard links and junction points. I
also don't expect a new CD/DVD file system to appear any time soon. As
DVD's get much larger (past the 30 gig planned) then maybe a new common
file system will be done that has many more features than CDFS/UDF. I
expect it might be something 64 bit based to last well into the future
and it would have to be an ISO based standard to be widly adopted.

Leonard Severt

Windows 2000 Server Setup Team
Click to expand...
 
I appreciate your answers Leonard, even though they weren't what I really
wanted to hear. However, even though we have a large investment in Windows
based software and related experience, it seems that the case for Linux just
keeps getting stronger...

Regards,
s/KAM


 
Researching this topic further, I see that both Windows 2000 and XP support
reading from disks formatted with the UDF file system, versions 1.5 and 2.01
respectively. I also found that UDF supports both hard links (level 1) and
symbolic links (level 2). So, now I'm wondering if there are any Windows
CD/DVD writing apps out there which actually support creating hard links
and/or symbolic links on UDF formatted disks...


Kevin Myers said:
I appreciate your answers Leonard, even though they weren't what I really
wanted to hear. However, even though we have a large investment in Windows
based software and related experience, it seems that the case for Linux just
keeps getting stronger...

Regards,
s/KAM
Click to expand...
 
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