Author Topic: Speeding up Par2 repair process  (Read 6001 times)

Offline zoned

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Speeding up Par2 repair process
« on: April 07, 2011, 05:35:21 am »
Quickpar doesn't seem to have an option to set to another drive location for the temporary working repair.

Neither has it a much needed alternative output on another drive. For saving out a complete repaired rar set, as unpacked rar files. It seems to do all its work using the source set location. Altbinz also seems to do exactly the same... Is it exactly the same as quickpar ?


The repair process could be much faster if user able to set a tempoary repair folder and repaired set save folder using three individual drives for speed repair.



A repair process example

|- rar set downloaded to drive D: using altbinz and now needing par2 repair
|
|- drive E:\Temp used for par2 repair - working folder
|
|- the rar files from the downloaded set and the repaired files from drive E:\Temp .After repair are then copied to drive F:\

Above drive examples are for drives not partitions, for fast repair

Offline Hecks

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Re: Speeding up Par2 repair process
« Reply #1 on: April 07, 2011, 07:46:34 am »
I don't really know why you would think such a setup would be "much faster". Given the usual repair scenarios, the speed gain would be tiny. The bottleneck in repairing isn't I/O.

Offline Rdl

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Re: Speeding up Par2 repair process
« Reply #2 on: April 07, 2011, 09:24:57 am »
Hecks is right. And if there is I/O bottleneck, it's on reading side(good blocks from complete files)

Offline zoned

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Re: Speeding up Par2 repair process
« Reply #3 on: April 07, 2011, 09:18:30 pm »
I thought it was i/o since both quickpar and altbinz can take over two hours to repair a 7gb rar set with five parts missing in five rars.

For exmple i note winrar will test the same file in seconds and say what rar files are bad. Quick par and altbinz takes a lot longer why! Isn't the checking only a verify test to check what is good or bad ? If any found bad uses the par files to repair those and make good rar sets.

Then the repair of those files using the pars with a lot of disk activity read and write from same drive. With big files this takes much time and a lot of hdd activity on 7200 pata drive is flat out working. This to me does seem to be i/o maybe using a seperate drives could help the process to be less hdd intensive and faster ?

Offline Rdl

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Re: Speeding up Par2 repair process
« Reply #4 on: April 07, 2011, 09:49:47 pm »
How can you compare checking file with repairing?
How can you compare winrar check where final result may be only that file is good or not good to par2 set check where you must also assume that any file, no matter the name or the previous block, can contain ANY block from the whole par2 set.
I already told you that I/O can be a bottleneck depending on the number of blocks/block size but mostly on read block side.

Familiarize yourself with the par2 process before going any further with this discussion!

Offline zoned

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Re: Speeding up Par2 repair process
« Reply #5 on: April 08, 2011, 08:13:50 pm »
I base my assumptions using the examples below, and yur right i know nothing of par2 process. Only that it can be very slow (last use with both quickpar and altbinz as above 7gb with only 5 missing blocks in five seperate 50mb rar parts) which both took over two hours to repair. Thought maybe could do with help using other drives as other softwares do to speed up processing files.


Examples

Use two drives for Non-Linear Video Editing (NLE)

Two drives for repair an archive, winrar repair using its recovery files (when available) repairs faster using two other drives, one for temporary working with and another for saving out the repaired file to.

XP os having the pagefile on another drive (seperate from the os drive). Better for no os drive bottlenecks when working with memory hungy softwares.

Offline useless

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Re: Speeding up Par2 repair process
« Reply #6 on: April 26, 2011, 04:52:20 am »
I thought it was i/o since both quickpar and altbinz can take over two hours to repair a 7gb rar set with five parts missing in five rars.

LOL Time to get a new pc.