Re: Selective Compression/Encryption

Miguel Figueiredo Mascarenhas Sousa Filipe
2008-12-09T15:45:10Z

Hi there,

On Tue, Dec 9, 2008 at 2:59 PM, Lee Trager <lt73@cs.drexel.edu> wrote:
> Currently compression and I assume if encryption is implemented it is
> turned on or off during mount. There are however many times when a user may
> want to select which files/directories they want to compress or encrypt.
> This will also be helpful when implementing btrfs support in grub for
> example. We can say the disk can be compressed/encrypted except for /boot so
> compression/encryption doesn't have to be implemented in grub.
>
> I was thinking of adding this functionality to the userspace application
> btrfstune. The way I was thinking of doing this is when btrfstune +c is
> applied to a directory or file the directory(and all its contents) or
> file will always be compressed reguardless of how the filesystem is
> mounted. The opposite would happen when btrfstune -c is used.
>
> Would this be a reasonable thing to implement? Any suggestions before I
> start doing this?
>

Things like compression or encription should be used at the "volume" level.
So.. if a user wants a specific set of files or dirs ..they should
create a mount-point/volume like:

private_vol
bigarchives_vol

and set those volumes as compressed or encripted volumes

Regarding usability, the best would be for the sub-volume creation
tool to optionally allow passing encription/compression arguments.

and then:
should mount those volumes somewhere like: ~/Confidential or ~/Archives.

Basically, do it at the directory level (which in btrfs is at the
sub-volume level).
File-level granularity is totally unmanageable in the long term.

Kind regards,

--
Miguel Sousa Filipe