Cameron Simpson wrote:
On 12Apr2008 13:15, Mike Wright <mike.wright@xxxxxxxxxxxxxx> wrote:
Hi all,
There was a fascinating thread about using ssh to do backups to a remote
host without using a term. Something like:
"tar jc some_dir | ssh -T user@remote cat > backup"
Tried the examples and then some --- works great!
I seem to have fat-fingered the delete key and have lost that email thread
and try for the life of me can't find it again.
Get rid of the -T. The "cat >backup" needs to be executed by the shell
at the far end, so quote it:
tar cf - some_dir | ssh user@remote 'cat >backup'
I don't think you totally understand -T, should be used whenever the
stdin is not a tty. Failure to do so can cause some issues with binary
files being transferred, from memory the binary can contain the escape
character.
From the man page:
"If no pseudo-tty has been allocated, the session is transparent and can
be used to reliably transfer binary data."
Mike - please ignore the advice to drop -T, it is not correct!!
Without the quotes your local shell takes the ">backup" and funnels the
data to the _local_ file "backup". So you pump the backup over the net
via ssh, and _back_ again, landing locally.
That advice is exactly correct. You can also use dd instead of cat, some
people claim that the buffering helps. I don't see it myself. ;-)
--
Bill Davidsen <davidsen@xxxxxxx>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot
