On Tue, Apr 03, 2001 at 03:54:15PM +0200, wojtek@wojtek.from.pl wrote:
> compressed speed depends of data and raraely is more than 2xuncompressed.

Yep..

> > Anyway, I couldn't fit more than 3.2 GB on a 4 GB tape (uncompressed
> > capacity), so something was (is?) wrong.
> 
> mt compress 1

Does it matter if the data has been gzipped already?

> > > tar cvf - <data to backup>|ssh host "dd bs=32k of=/dev/rst0"
> > 
> > Does dd do double buffering?  If not, the tape would stop streaming if
> > there was a slight delay in network or on the other machine?  I wanted
> > to use buffer because it does double buffering and simultaneous read/write
> > to the buffer.
> 
> tape drive has it's own buffer (mine about 1MB)

I'm trying with "dd bs=32k" now.  I have tried using "buffer" with bufsizes
up to 8 MB and blocksizes of 10k, 32k, and 256k.  This is what I usually
get:

buffer (writer): write of data failed: Input/output error
bytes to write=262144, bytes written=-1, total written    3216384K
Connection to tmp closed by remote host.
187.602u 94.750s 2:14:53.14 3.4%        0+0k 258+53io 75pf+0w

If I run tar on the system with the tape drive, I can fit much more data on
the tape (same data, that is).  Weird..

  -jm