Sparse files conversion 1

[JulesBirch]

Hi

I am trying to read files created by a Pervasive database application in a NetWare 4.11 environment into a Windows 2000 Server environment. I have taken a tape backup of the database data in the NetWare environment and am attempting to restore it to the Windows environment.

The software that is restoring the tape to Windows is Backup Exec and it is complaining about “Sparse files” and is erroring. I have contacted Backup Exec support and they can offer no help with this.

It seems that NetWare writes these sparse files in a database environment. Is there any way that these files can be converted into a Windows compatible format within NetWare or any switch or command that I can issue on the NetWare server to persuade NetWare to write files in a more conventional format?


Failing that, is there any utility that I can use in a Windows environment that can read NetWare sparse files?

Any help on this would be greatly appreciated.

Regards

Jules

 

[marvhuffaker]

Why don't you just forget about the tape backup and copy directly from the Novell server? Take out the middle man.

Marvin Huffaker MCNE, CNE
Marvin Huffaker Consulting, Inc.

http://www.redjuju.com/support

 

[JulesBirch]

Hi

I think that the file would still be in NetWare Sparse file format which I don't believe is compatible with NTFS.

I am led to believe that it needs to be converted.

However, if you know different I would be happy to try a direct copy.


Jules

 

[marvhuffaker]

What are sparse files? - TID10064500 (last modified 27MAR2002)
goal

What are sparse files?
fact

Novell NetWare 4.11

Novell NetWare 5.0

Novell NetWare 5.1

Novell NetWare 6.0

Formerly TID 1202723
fix

A sparse file is a file with lots of empty space inside the file. NetWare doesn't store most of this empty space, so it is possible to have a very large file (with lots of logically empty space), but have it take up only a small amount of space on the server.

Such a sparse file can be created if a program was to open the file and seek (move the file pointer) way beyond the end of the file, and then write at least one byte. In SoftSolutions this could possibly happen to a database file if an index pointer into that file were possibly corrupt beforehand. For example, suppose we have an index pointer pointing to record #1,048,576,000 when it should be pointing to record #205. If we then try to access this record we would seek beyond the end of a file, and possibly even attempt to write some information there. If the write, of at least one byte, is successful then we would have created a "sparse" database file with a seemingly incorrect file size.

This scenario is very rare but when encountered there are three courses of action:
1) Sometimes a COPY or XCOPY out and back will fix the problem (copy it to a temporary location and then copy it back into the original location).
2) Perform a NORMAL reconstruction on the sparse file (a SpeedSearch reconstruction if the file involves a KDT file). Files like PROFILES.*, WORDS.*, or *.KDT, will usually involve a reconstruction.
3) Restore it from a backup. A restore from backup works with files that get updated rarely, like SCREEN.* or any of the other files for the setup options. If the sparse file is not a setup file (eg. Profiles.dat) but you would like to restore it from backup then you must restore the entire data directory.

Since sparse files are caused by corruption, the best approach at preventing this scenario is to implement standard safeguards against corruption. These are things like insuring that backups are taking place without users in the system, enabling TTS, and using a SoftSolutions SEM.

Marvin Huffaker MCNE, CNE
Marvin Huffaker Consulting, Inc.

http://www.redjuju.com/support