[RFE] - scrub only used blocks in sparse files

[GoogleCodeExporter]

This would be an RFE to have the ability for scrub, to only scrub the used 
blocks in a sparse file.

What version of the product are you using? On what operating system?

2.4.1 - Linux x86_64 (RHEL 6.2 Workstation)

Please provide any additional information below.

We have thousands of servers that have information stored in sparse files, as 
part of our security they need to be scrubbed each night.  If we where able to 
only scrub the used blocks that would be a tremendous time saver.

Thanks,
Jacob

Original issue reported on code.google.com by jacob.r....@gmail.com on 19 Jan 2012 at 4:03

[GoogleCodeExporter]

The only POSIX way I can think of to do that is to first read the file as 
though it were not sparse and map out all the blocks that read as zero, then 
skip the zero blocks in subsequent passes?  It'd have to be a new option, 
disabled by default.

There's no way to differentiate between unused areas of the file and content 
consisting of zeros, so enabling this would be too relaxed for compliance with 
the letter of the various overwrite "standards".

Maybe I'm missing a better way to do this? 

Original comment by garlick....@gmail.com on 19 Jan 2012 at 4:25

• Changed state: Accepted