From: Kern S. <ke...@si...> - 2009-12-03 12:46:58
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>> >> > Kern Sibbald wrote: >> >> On Monday 23 November 2009 19:36:10 Steve Polyack wrote: >> >> >> >>> Steve Polyack wrote: >> >>> >> >>>> I've simply added another configuration option for any Storage {} >> >>>> resource in the Director's config. An admin may set >> >>>> AllowCompression=No for a particular storage resource, causing > the >> >>>> director to prevent any GZIP compression options from being sent > to >> >>>> the FD when a job is run against that particular storage > resource. >> >>>> The default for the directive is Yes/true so that behavior is >> >>>> unchanged for anyone who does not choose to set it. There may be > a >> >>>> better way to strip the compression flags from the fo->opts[] > going >> >>>> out to the FD, but this works great and appears readable to me. >> >>>> > > What happens with a migrate/copy from a storage that supports > compression (as per your new option above) to one that doesn't, or the > other way around? I assume nothing different as this is an option that > impacts the FD only right? > > Ideally, if you copied an uncompressed job from tape to disk, you might > like the option to compress the job if it wasn't compressed already (not > possible at the moment afaik as the compression is always done on the > fd?). > > If you copied a compressed job from disk to tape (a much more likely > scenario) the job should stay compressed (no point undoing the > compression 'effort'), but the hardware compression on the tape drive > itself should be disabled. AFAIK, bacula has no way of turning tape > drive compression on or off at this time though. > > If the items in the above two paragraphs are addressed at any time in > the future, the AllowCompression option would need to be in the > bacula-sd.conf file right? For copy and migration jobs, Bacula simply copies the raw data. It does not look at any of the details. If the output device has hardware compression turned on, the output to the device will be compressed. Basically, hardware compression/decompression is transparent to Bacula. Best regards, Kern |