[ale] Re: backup

[Gary Maltzen]

AFAIK, IRIX implements *real* (not *Redmond*) pipes, so it should work fine.
The pipe ("|") connecting the two processes just holds a finite number of
bytes in memory; there is no intermediate file written.

Try adding the "v" option to the extract ("tar xvf") so you can see where it
breaks.

Make certain that "todir" isn't in the "fromdir" subtree...

Make certain that "fromdir" doesn't include /proc or other
psuedo-directories...

-----Original Message-----
 From: Marc Vogt <mtv at theor.chemistry.gatech.edu>




Thanks to all of you who responded to my post concerning
an 18 Gig backup.



>I think what you meant to say was:
>   cd fromdir ; tar cf - . | ( cd todir ; tar xf - )
>I don't know where the "i" came from in there.


the "i" came from the HPUX man page for tar.  Serves me right
for doing that.  This backup is actually for an IRIX system.


also, the command as clipped and pasted above works fine.
Thank you very much for it and the clarification.

I guess my only quaetion now is, say that the backup as performed
this way dies in the middle of the process.  How does this
work?  Does it create an archive for one file and then extract it?
Or does it work so many bytes at a time?  Either one of these would be
okay (depending on the size of the pieces it works with), but if
it is the case that it makes one big bundle and then extracts it,
might I not get screwed if it dies in the middle?





>Are you trying to have 2 drives that contain exactly the same thing to
>protect against the physical hardware crashing? If so, you might want
>to look into the software-RAID stuff (there's an option for it when
>configuring the 2.2 kernel). You want RAID level 1.


yes, and do they have this for IRIX?





>I have used the "find" command to find all files created
>after a certain date that are of a certain type and feed
>them into "tar".


I've done something like this before and I like the idea.
Thanks.



>Check out rsync.

Never heard of it, but we do have it and it sounds like a possibility.
Thanks.



>Could you not somehow use mirror?

I can't see that we have a command "mirror" for IRIX 6.4.
But mirroring is essential what I would like to do.
I guess I'll use tar for now and look into rsync and mirror for the future.



thanks

Marc