[CentOS] Tape drive throughput

Fri Jun 9 20:42:41 UTC 2006
Bowie Bailey <Bowie_Bailey at BUC.com>

Rodrigo Barbosa wrote:
> On Fri, Jun 09, 2006 at 04:15:38PM -0400, Bowie Bailey wrote:
> > Rodrigo Barbosa wrote:
> > > On Fri, Jun 09, 2006 at 03:56:36PM -0400, Bowie Bailey wrote:
> > > > I have a backup spooling onto a DLT drive.  Is there any tool
> > > > that will let me monitor the data throughput on the device?
> > > 
> > > Throughput on a tape drive is very variable, depending on how you
> > > are writing/reading the data to it.
> > > 
> > > So for some meaningful numbers, you would need your backup
> > > solution to provide them.
> > 
> > I'm just looking for raw bps flowing to the device.  I don't really
> > care about compression and such at the moment, I just want a rough
> > idea of what the drive is doing.
> 
> There is no such thing. You "raw bps" will vary greatly depending on
> your blocksize and other factors.

I don't follow.  The backup program is writing data to the device.
Regardless of how complex that data stream is, there is a specific
amount of data that is transmitted in a given period of time.

This would be like sticking a meter inline on an ethernet cable and
simply counting bits.

There may or may not be a tool to do this and it may or may not be a
useful measurement, but it should be possible.

-- 
Bowie