In message <20050511133925.GA46856@lori.mine.nu>, "Geert Hendrickx" writes:
>On Wed, May 11, 2005 at 09:18:53AM -0400, Steven M. Bellovin wrote:
>> In message <20050511122013.GA46029@lori.mine.nu>, "Geert Hendrickx" writes:
>> >Hi, 
>> >
>> >the manpage for restore says the following: 
>> >
>> >> The fastest way to extract a few files is to start with the last
>> >> volume and work towards the first volume.
>> >
>> >I don't see why...  
>> >
>> 
>> The backup directory is at the beginning of the first tape; restore
>> looks up the inode numbers.  Each tape starts with a header saying
>> what inode the tape start with.  Just looking at that header can tell
>> you that the inode number you want isn't on that tape; it's too low.
>> That saves the effort of reading that entire tape.
>
>So, when you go from the first volume to the last, restore would argue:
>the wanted inode number is bigger than the start-inode number of this
>volume, so it _could_ be on this volume; let's look through it entirely.  
>For each volume until the right one.  
>
Precisely.

		--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb