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[rdiff-backup-users] bzip2 and 7zip ?

From: Marian 'VooDooMan' Meravy
Subject: [rdiff-backup-users] bzip2 and 7zip ?
Date: Sat, 14 Aug 2010 13:38:06 +0200
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ping? No response over time...

I know that 7zip has "ultra compression" profile algorithm, which eats
up all your CPU, but today, there are multi-core systems - of which 7zip
is able to take advantage - it is muti-threaded, and it should be fine
to set configuration option (command-line option) to chose from 1. gzip
(as now it is this way), or 2. bz2, or 3. 7zip and in case of 7zip the
"depth" of compression + how many threads (cpu cores) the 7zip should
use and of what niceness. It is always up to the user, whether they want
simple and fast compression, or deep compression && don't mind about
excessive CPU load - in docs, they always can be warned... it is the
matter of priorities and backup operator's preference and decision...


On 11. 8. 2010 20:16, Marian 'VooDooMan' Meravy wrote:
> Greetings,
> devels: rdiff-backup stores data by using industry standard "gzip". But
> bz2 has better compression. Or even usage of 7zip, which is not
> "industry standard" but everyone is using it, so it will become industry
> standard sooner or later, and it has more aggressive compression than
> all other zip algorithms (it has even multi-thread support, so SMP
> kernels and multi-core systems can use advantage of it). PS: 7zip AFAIK
> has library installed besides command-line tool `mc` - midnight
> commander is using it) -> I'm not sure about .so library, but I'm really
> sure that bz2 package _HAS_ library, I mean .so on unices, on windows,
> there should be .dll as well).
> would it be possible to implement bz2, or even 7zip ?
> on windows installation (e.g. cygwin) can place dependency for
> compression libraries...
> Best,
> VooDooMan
> .
> On 11. 8. 2010 20:00, Steven Willoughby wrote:
>> On 08/10/2010 04:16 PM, Robinson, Eric wrote:
>>> "It's quiet."
>>> "Yeah, too quiet. Gives me the willies."
>>> "Me, too."
>>> -- 
>>> Eric Robinson
>>> -----Original Message-----
>>> From: address@hidden
>>> [mailto:address@hidden
>>> On Behalf Of Robinson, Eric
>>> Sent: Saturday, August 07, 2010 8:50 AM
>>> To: address@hidden
>>> Subject: [rdiff-backup-users] Error "Unable to compare" BUT THEN "No
>>> changesfound. Directory matches." What?
>>> I've been using rdiff-backup for a while, but today was the first time I
>>> tried using the --compare-hash directive.
>>> First I get tons of these messages...
>>>     Warning: Metadata file has no digest for<file>, unable to
>>> compare.
>>> That's scary enough by itself. But then at the end it says...
>>>     No changes found.  Directory matches archive data.
>>> So if it can't compare, why would it say the directory matches?
>> I have been running rdiff-backup for a long time with the --verify
>> option which does something similar with no issues.  The --compare-hash
>> option also seems to be working perfectly for me.  Adding -v6 to your
>> command might be enlightening.
>>> And what is the problem with the hash in the first place?
>> The hash should be stored in
>> $backup_dir/rdiff-backup-data/mirror_metadata.$date.  Try looking at the
>> mirror_metadata snapshot previous to the current one (you should be able
>> to open it with zless or zcat).  IIRC older versions of rdiff-backup
>> (like 1.0) didn't store this hash, so perhaps it is missing.  If that
>> was the case then that would explain the warnings and the "No changes
>> found." is probably a bug since it didn't find any files that didn't
>> match (since all of them were skipped.)
>> It might work to use the --compare-full option if you haven't been
>> storing hashes.
>> Steven
>> _______________________________________________
>> rdiff-backup-users mailing list at address@hidden
>> http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
>> Wiki URL:
>> http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki
>> _______________________________________________
>> rdiff-backup-users mailing list at address@hidden
>> http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
>> Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki

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