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Old 12-03-2013, 01:27 AM   #1
sachin.davra
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compression in ssh session


Can you please lemme know how to increase the compression level per ssh session?
what is the benefit of using compression in ssh session?
 
Old 12-03-2013, 01:39 AM   #2
evo2
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Hi,
Quote:
Originally Posted by sachin.davra View Post
Can you please lemme know how to increase the compression level per ssh session?
for modern openssh (ie not ssh 1), compression is either on or off. It can be turned on with the -C flag. See the man page for more information.
Quote:
what is the benefit of using compression in ssh session?
Decrease in the amount of data transferred.

Evo2.
 
Old 12-03-2013, 01:41 AM   #3
sachin.davra
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Quote:
Originally Posted by evo2 View Post
Decrease in the amount of data transferred.
Evo2.
Thnx for the update. i am not using v1 so it can be enabled or disabled in my case.
suppose i transfer 3GB data then how much compression will be done? Will it take less time to transfer 3GB file?
 
Old 12-03-2013, 01:53 AM   #4
evo2
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Hi,
Quote:
Originally Posted by sachin.davra View Post
suppose i transfer 3GB data then how much compression will be done? Will it take less time to transfer 3GB file?
openssh uses gzip for compression, so you can find out exactly how much the size is reduced just by gzipping the file.

Note that the compression ratio varies wildly with the type of data. For example if the files a just text, then the compression ratio can be excellent. However if for example they are image, video or audio files that are already in a compressed format you are not likely to gain much size reduction. In this latter case the over all transfer time is likely to increase because of the overhead of the time it takes to compress (and to a less extent decompress) the data.

Evo2.
 
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Old 12-03-2013, 01:55 AM   #5
sachin.davra
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Quote:
Originally Posted by evo2 View Post
Hi,

openssh uses gzip for compression, so you can find out exactly how much the size is reduced just by gzipping the file.

Note that the compression ratio varies wildly with the type of data. For example if the files a just text, then the compression ratio can be excellent. However if for example they are image, video or audio files that are already in a compressed format you are not likely to gain much size reduction. In this latter case the over all transfer time is likely to increase because of the overhead of the time it takes to compress (and to a less extent decompress) the data.

Evo2.
Thnx for the info.
 
  


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