Re: [cobalt-users] tar

[flash22@xxxxxxx]

On Sun, 10 Feb 2002, Jim Carey wrote:

> I have a backup script that I am using that creates the output .tar.gz files in two steps:
> 
> tar -cpPf
> gzip -9 -S .gz
> 
> is there any speed or size difference is using the two step process rather than a one step:
> 
> tar -cpvz
> 
> method ?

Speed , yes, tar is mostly disk bound, so there is cpu time left over,
combining with -z allows the machine to do the compression while it's
goofing off waiting for the disk...

However, if the machine is a production server, using all the available
cpu resources probably isn't a desired goal anyhow ;P

Size should be identical, assuming you are using the same compression
level that both default to, but you are using -9 , tar defaults to
gzip's default, tho you can pass it this info if you want....
(Set GZIP="-9" before running tar, gzip reads it from the environment)

You realize that this level of compression almost triples cpu usage, and
usually gets only a few percent betetr compression ;P

gsh