[comp.unix.microport] backup procedures

alan@k0jfv.UUCP (Al Kiecker) (09/24/88)

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		
WORK: 	uunet!rosevax!bungia!sx1100!alan		(612)635-2574		
HOME:	uunet!rosevax!corum!k0jfv!alan			(612)432-8139

kjk@pbhyf.PacBell.COM (Ken Keirnan) (09/26/88)

In article <101@k0jfv.UUCP> alan@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@pbhyf.PacBell.COM

tkevans@fallst.UUCP (Tim Evans) (09/27/88)

In article <101@k0jfv.UUCP>, alan@k0jfv.UUCP (Al Kiecker) writes:
> 
> 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?
> 
cpio is asking for the device name again here.  For example, if you're
using the hi-density floppy (1.2 meg), enter:

	/dev/rdsk/fd096

Or whatever you entered when you initiated the cpio.  (Why someone made
this hard is a good question to consider.)

> Can tar be used?
> 
Although some vendors' 'tar' allows you to specify a size for your backup
device (in blocks), uport's does _not_.  Thus, if the data you're backing
up runs more than 1.2 megs (for a high-density floppy), you're out of 
luck.

-- 
UUCP:  ...!{rutgers|ames|uunet}!mimsy!aplcen!wb3ffv!fallst!tkevans
OTHER: ...!attmail!fallst!tkevans
Tim Evans  2201 Brookhaven Court, Fallston, MD  21047   (301) 965-3286

det@hawkmoon.MN.ORG (Derek E. Terveer) (09/27/88)

In article <101@k0jfv.UUCP>, alan@k0jfv.UUCP (Al Kiecker) writes:
> I would like to be able to do some sort of selective backup: 

Tar or cpio are probably pretty good choices.

> 	- why backup what is on your distribution disks? 

If you get updates to the distribution software, you'll want those backed up.
It may be simply too much trouble to sort out exactly what is on the
distribution vs. user's files, your additions, your mods (to the dist software,
for example, /etc/passwd), etc.  Its easier to just back up the whole kit and
kaboodle (in general).  Also distribution diskettes *can* go bad -- just like
any other disk.

> 	- what sort of disaster could befall me if I don't backup 
> 	  /usr/spool/news/...? 

Generally, just a loss of the current news articles for your site and any down-
stream sites, if any.

> 	- or why backup something if I have it on a previous backup 
> 	  and I have not modified it since then?

Thats why you can perform an incremental save.  Once every so often, be it a
week (like lily and herman) or once a month (or once every two years like alta
and bigsky) do a FULL save which saves everything.  Then, every day or every
few days, do an INCREMENTAL save which saves everything that has changed since
the fullsave.  You can do this with a command *like* the following:

$ find / -newer full_save_time -print|cpio -ocvadm >/dev/rdsk/fd0

> 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?

It *is* asking you to put in a new floppy.  But cpio is more flexible than you
think.  What if you have >1 floppy drive?  (what if you had 5 floppy drives or
perhaps 3 tape drives???), then if you want to ready your second floppy in
drive #1 while the floppy in drive #0 is being written, you can do so.  When it
prompts you, you enter the device name of floppy #1 and off it goes (with
floppy #1).  Then while its writing floppy#1, you ready floppy #0 and enter
that drive name at the prompt when its requests you to do so.
Cpio will work with tape drives, etc., not just floppies, albeit you only have
a floppy on your system -- some systems do have >1 floppy in their peripheral
set (:-)

> Can tar be used?
yes.

> I don't think volcopy will give me the selection capability that I want.

no, it won't.  volcopy does a literal fs copy.

derek
-- 
Derek Terveer		det@hawkmoon.MN.ORG
			w(612)681-6986	h(612)688-0667

"A proper king is crowned" -- Thomas B. Costain

carvalho@ernie.Berkeley.EDU (Marcio de Carvalho) (09/29/88)

If you want to avoid havig to type the floppy device name
every time you change, you may use the undocumented program
ncpio, as:

	ncpio 'options' -I/dev/diskette 

I discovered this by browsing thru the sysadm script files...
Have fun.

--Marcio
=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=
=                          Marcio de Carvalho                              =
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= ...!ucbvax!ernie!carvalho          University of California at Berkeley  =