Re: [SLUG] Travan tapes under GNU/Linux (Debian Woody)

["Oscar Plameras" <oscarp@xxxxxxxxxxx>]

From: <mlh@xxxxxxxxxxxxxxxxxxx>
Sent: Tuesday, May 13, 2003 8:01 PM
Subject: Re: [SLUG] Travan tapes under GNU/Linux (Debian Woody)


> On Tue, May 13, 2003 at 10:50:03AM +1000, Oscar Plameras wrote:
> >  [ .. ]
> > In my case, I prefer to re-state the same command into,
> > 
> > tar zcvf /dev/tape -T `find /home -mtime -10` | tee /tmp/tape.log
> 
> Ouch!
> 

What's wrong ?

I made a test script below. This demonstrates that 

tar zcvf l.tar -T `find /var/log` | tee.log 

is perfectly correct with its syntax and is working correctly.

Script is slightly modified to avoid using tape and to avoid 
outputing too much on stdout. This is to demonstrate that
the syntax is correct and backup correctly.

#!/bin/bash
cd /home
tar zcf l.tar -T `find /var/log` | tee l.log
tar zxf l.tar
ls /var/log  | wc 
ls var/log | wc 
/bin/rm -rf var

Output:

69  69  599
69  69  599

This demonstrates the command backup correctly.
You may replicate this test in your machine.

> -T specifies a file containing a list, not a list itself.
> And using backticks will fail, possibly without a useful
> error message if the output is too large.
>

If output is too large it will give an error that says,

bash: /bin/tar: Argument list too long

Note that there is a restricting parameter of,

-mtime -10

which means that only files that were modified for up
to 10 hours ago will be included. The rest are excluded.
And so the list size is small.

Whether the directory is large or small is not an issue 
as to whether the command is correct or not in its
syntax.