[SWLUG] Backing up took 3 days

[Steve Hill]

On Mon, 5 Dec 2005, James wrote:

> Someones also told me that the choice of flags are unusual, specifically the 
> 'f' flag - "force file to be copied if the destination file cannot be opened" 
> - that to me sounded like "if the destination file is corrupt, retry". Am I 
> wrong in thinking like that? I read through the man pages but could not find 
> what was wrong with the command.

When cp overwrites an existing file it does it by modifying the file which 
is already there.  If the destination file is an executable and is 
currently executing you aren't allowed to modify it so that will fail. 
the -f flag makes cp actually delete the existing file before overwriting 
it and it is allowed to do that even if the file is executing (because 
deleting files which are in use doesn't really remove them from the disk 
until they have stopped being used).

I don't really see anything wrong with using -f on a backup <shrug>.

> I was also told that the cp command should copy all files which the ln 
> command will see, with the same parameters. For example:
>
> ln -R /home/james/*
>
> Lists everything in my home directory, but:
>
> cp -fvr /home/james/*
>
> ignored anything beginning with a dot.

I assume you mean "ls -R /home/james/*" rather than "ln".
In any case, if "ls -R /home/james/*" is listing the dot-files in 
/home/james then I don't know why because it shouldn't.  The 
"/home/james/*" bit is known as a glob and is expanded by the shell 
itself, regardless of the command.  You can do "echo /home/james/*" to see 
what the shell expands it to, but the '*' wildcard never contains files 
starting with a dot (at least, under Bash it doesn't, and that's almost 
certainly the shell you're using).  You could just backup /home/james 
rather than /home/james/* since that would grab the directory and 
everything inside it.

-- 

  - Steve
    xmpp:steve at nexusuk.org   sip:steve at nexusuk.org   http://www.nexusuk.org/

      Servatis a periculum, servatis a maleficum - Whisper, Evanescence