lastlog devours universe

[Michael Wiktowy]

Matthew Miller wrote:

>On Wed, Jun 08, 2005 at 04:37:32PM -0400, Michael Wiktowy wrote:
>  
>
>>I don't really see that as being unreasonable. However, I don't have a 
>>lot of experience with using tar to backup though. In your experience, 
>>is there a reason not to use --sparse in most occasions?
>>    
>>
>
>It's probably somewhat slower to have to check if special handling is
>needed.
>  
>

Previous messages in this thread indicate:
- there is a small perfomance hit
- sparse files take a long time to compress (although they *do* compress 
really well).

So it seems like there might be some time gain to be had if you are 
ultimately compressing the tar. This seems like a typical thing to do. 
Maybe --sparse should be assumed if a -z or -b is picked so that those 
foolish novice system admins are not burned by a performance hit. This 
is something that needs to be backed up with actual testing results 
comparing the two methods.

Other than speed, are there other issues with assuming --sparse?
What are the reasons for explictly *not* using --sparse? Do checksums 
get messed up?

/Mike