[OpenAFS-devel] Patches for Openafs compression support

[Jeffrey Hutzelman]

On Wednesday, January 05, 2005 12:39:33 -0500 Mitch Collinsworth 
<mitch@ccmr.cornell.edu> wrote:

>
> On Wed, 5 Jan 2005, Jeffrey Hutzelman wrote:
>
>>> Do we want to implement compression as seperate calls for every thing
>>> that we want to compress or should we be able to switch it on/off
>>> like encryption?
>>
>> Actually, what I'd like to see is an extension to the dump file format
>> to  allow for compressed dumps.  In this model, "new" volservers would
>> automatically generate compressed dumps if the feature was enabled, and
>> would  always be able to accept either kind of dump.  No new RPC's would
>> be added  (*), and no changes to any clients would be required.  The
>> compressed part of  the dump should begin with the vnodes, leaving the
>> dump and volume headers  uncompressed for tools which expect to be able
>> to parse these.
>
> Thank you!  This is what I'm concerned about.  Our tools to backup AFS
> using Amanda parse the dump file format in order to generate an index
> of files.  If the volume headers are kept uncompressed then this should
> not be a problem.

Hm.  Stage parses the dump header to get timestamps and the like, but we 
haven't gotten around to file indexing yet.  Creating a file index would 
require parsing the (presumably compressed) directory vnodes.


> Of course the other solution would be an interface that does the dump
> file parsing and presents a consistent API for external tools to use.
> Then we wouldn't need to be on guard against file format changes.  :-)

/afs/cs.cmu.edu/project/systems-jhutz/dumpscan

But I really should do a formal release one of these days.

-- Jeff