On 20/04/2013, at 2:59 AM, gunnerjoe <networker-forum AT BACKUPCENTRAL DOT COM> 
wrote:

> Hi All,
> 
> Thank You for all your replies.
> 
> So, looking at my system trying to figure out what is actually doing the 
> compression I'm seeing.
> 
> Setup:
> Win2k8_64 Legato 7.6.4 server
> Tape Library  HP MSL2024
> Windows Clients with NT Standard Directives in the client config.
> ===
> 
> A line out of the HP MSL2024 Tape Library documentation says the following:  
> Data Compression — Yes, if the host has hardware compression turned on for 
> the drive.
> 
> Ok back to Legato /  Networker Management Console / Networker Administration 
> / 
> 
> The only thing I can find about compression is under Global Directives in the 
> Left Pane,
> 
> /Directives / NT With Compression Directive 
> 
> << / >> 
>       +compressasm: .
>       
> Is this the primary place to control compression of files being written to 
> tape? Or is this Directive only active when applied in the client config and 
> only compresses data being sent over the ethernet from client to server?
> 
> My apologies if this question is obvious to everyone but me.

The compressasm directive (and the more recent directives for performing gzip 
compression or bzip2 compression) only apply if you're trying to do 
software/client-controlled compression.

With a backup product, you'll enable one or the other, but not both. Due to the 
higher CPU load placed on clients that are compressing their own data, it's 
typically recommended to only turn on client side compression in very 
particular circumstances. If the data is going to tape, which it is in your 
case, then you're best off using the tape compression functionality.

Cheers,
Preston.