Sparse files support

Jan 25, 2014 at 8:36 AM
I have tried using Liquesce with sparse files, but I have encountered some strange behavior.

1) Sparse files written to the underlying discs have incorrect "Size on disk" in the properties window when accessed from the virtual pool drive (shown equal to the "Size" field).
The size on disk is reported correctly on the underlying drive.

2) Renaming the sparse file (in Total Commander) caused it to be moved to a different underlying drive and expanded to it's full size (the file stopped being sparse). Also, during this rename (which took approximately 20 minutes for a 100 GB file) the whole windows explorer (with the virtual pool drive opened) as well as Liquesce Mount Manager with service tail opened stopped responding for the whole time.

3) Copying a sparse file from an independent drive (not part of Liquesce setup) to the virtual pool drive using "cp -a -u source target" in Cygwin caused the following warning (after writing the data first):
cp: writing 'target': Permission denied
cp: failed to extend 'target': Permission denied

After that, it apparently tried copying the file without preserving the sparseness (the virtual pool drive stopped responding again during this time). The file was successfully copied to the drive but it grew to it's original size (stopped being sparse).
Writing to one of the underlying drives instead worked without problems.

I didn't try copying a sparse file in place as writing it there didn't work already. There is (AFAIK) no simple way to copy a sparse file on Windows (CopyFileEx inflates the file by default), but cp in Cygwin works just fine for example.

It would be great if you could support at least the correct file size (GetCompressedFileSize in winapi perhaps).

I understand that this kind of functionality isn't a priority for most users though :)

PS: Used the latest version.
Jan 26, 2014 at 7:34 AM
This discussion has been copied to a work item. Click here to go to the work item and continue the discussion.
Jan 26, 2014 at 7:36 AM
Thanks for the report.
Can you add the following to the above issue link please.
OS version.
Log's (Set to Trace) and the timestamps of when relevant points (Use smaller files :-))
And you state latest, can you clarify which ?

Thanks in advance.