Re: Odd thing about restore times

[Bob Eager <rde@tavi.co.uk>]

On Fri, 23 Nov 2018 17:35:06 -0800
Craig Hartnett <craig@1811.spamslip.com> wrote:

> Hi there,
> 
> This email was going to be a (mild) complaint about restore times, but
> then I noticed an odd thing: If I restore a directory with about 30
> full-size, full-resolution images, the directories in the path to the
> directory I restore are all created within about 45-90 seconds, and
> then the files start coming down at roughly the rate I might expect
> for files of about 2 MB each. The files were all restored within
> about 5 minutes. If I restore a single, small text file, it is
> restored in seconds.
> 
> Yet in both cases, the command does not exit for about 16-21 minutes,
> which is what was going to lead me to complain. However, the actual
> restore was done about as quickly as one would expect.
> 
> In all test cases I used the following command:
> 
> 	tarsnap -x -f ARCHIVE media/USER/PATH/DIRECTORY
> 	tarsnap -x -f ARCHIVE
> 	> media/USER/PATH/DIRECTORY/FILE.EXT
> 
> Is it possible I'm doing something wrong, or is this a known bug?
> There is nothing mentioned at
> http://www.tarsnap.com/improve-speed.html that would seem to be about
> this.

I am guessing to some extent, but I would imagine that tarsnap is
scanning to see if there is a more recent version of the file in the
same archive (this is possible with tar, anyway, and I suppose that if
you give the two names to tarsnap it will do the same).

I wonder what happens if you use:

  tarsnap -x -k -f ARCHIVE media/USER/PATH/DIRECTORY