backup procedures

[Ken Keirnan]

In article <101 at k0jfv.UUCP> alan at k0jfv.UUCP (Al Kiecker) writes:
>I would appreciate hearing any suggestions that anyone could make on 
>recommending a process to use in performing backups to floppies. 
>
>I would like to be able to do some sort of selective backup: 
>
>	- why backup what is on your distribution disks? 
>	- what sort of disaster could befall me if I don't backup 
>	  /usr/spool/news/...? 
>	- or why backup something if I have it on a previous backup 
>	  and I have not modified it since then?
>
>
>What is cpio asking for when it gets to the end of a floppy and asks
>"If you want to go on, type device/file name when ready" ? Why can't
>it just ask you to put in a new floppy and then continue?
>
>Can tar be used?
>
>I don't think volcopy will give me the selection capability that I want.
>
>Thanks for your help.
>
>						-- al
>-- 
>Al Kiecker		



You should always (repeat *always*) have backup copies of your distribution
media somewhere.  If you do, then backing up every directory on your system
for a normal backup may be unnecessary.  However, there are some "system"
directories containing files that change regularly such as "/etc" so watch
out!

You might want to split backups into "epochs" and "incrementals".  A
simple mechanism for doing this is to perform a full "epoch" backup (the
works) using cpio, followed by directing the date to a file, for example,
/etc/epoch_date.  To perform an "incremental" backup, use the "-newer"
option of the find command to locate files newer than (or modified after)
the /etc/epoch_date file:

	find <directories> -newer /etc/epoch_date -print | cpio ...

This will keep you up to date and keep the frustration factor low.  Note
that <directories> can be "." from the root directory to examine everything,
or one or more specific directories for performing selective backups.
Procedures like the above are good candidates for shell procedures.
Epoch backups should be done at regular intervals (Once a month? Every
two months?) to have an accurate snapshot of your system.  Remember,
incremental backups don't get rid of files deleted since the last epoch.

Whenever cpio believes it has reached the end of medium when writing to
or reading from a device, it will prompt for the next place to write to
or read from.  On systems with multiple backup devices (usually tape)
this allows for cpio to continue on a different drive while changing media
on the first.  In your case, change floppy disks and specify the same
device each time.

Tar (if my memory is still with me) doesn't handle multiple tapes or disks
well and doesn't copy empty directories or special files.  Please no flames
if I am incorrect - I use tar infrequently.

Volcopy performs "binary image" copies of file systems.  This makes volcopy
unsuitable if you require the ability to extract single files or directories
from the backup media.

I can't help you with your question about /usr/spool/news since I don't
administer our news feed.  Sorry.

Ken Keirnan
-- 

Ken Keirnan - Pacific Bell - {att,bellcore,sun,ames,pyramid}!pacbell!pbhyf!kjk
  San Ramon, California	                    kjk at pbhyf.PacBell.COM