Backing up multiple user data

[Janina Sajka]

Luke Davis writes:
> Hmm.  If I recall correctly, tar can save files on remote hosts.
> 
> How does it accomplish this?
> (not "how do you do it", but "how does it work".)
It turns out to be disarmingly simple. tar can read and write std io. I
always thought that was a strange feature. I don't think that anymore.

Turns out this stuff is as old as the hills. Until I started looking at
books from BookShare, I was Googling. Amazing. The files I pulled up
were old "Introduction to the Internet" kinds of things from the early
1990's. It was rather fun seeing those old html 2.0 files again. They
were really so much more blind friendly back in the days before the nav
bar was invented to our detriment.

But, I diagress.

It seems the original purpose was to access a tape mechanism on a remote
server. Makes sense. Tape drives are expensive. You wouldn't have one
per machine. So, the missing app in my earlier attempt to write tar
output to HOSTNAME:test.tgz would have been rmt.

Indeed, I also found this little gem on line:

tar cf - filename  | ssh -l userid hostname 'dd of=/dev/tape'

The comment accompanying said "This works under SGI Irix and OpenSSH, and should under Linux."

Last point, the ssh part is also pretty impressive. If you don't have
it, get the ssh book from BookShare and look at Chapter 9, the chapter
on port forwarding. Seems one can direct any kind of process as long as
it's tcp. udp won't work, but tcp will.

 
>