Backup Central

We've got 16 tapes in a tapecycle of 5 over a week (cron runs once a
weekday, runtapes is 1), and we're trying to keep enough tapes offsite
such that there's everything required to do a full restore from the
latest backup of all machines... this should be 5 tapes, but sometimes
grows when a flush is run.

So I'm wondering if there's a amadmin command or somesuch that we can use
that'll tell us which tapes are in the set of tapes required to do a full
restore from, i.e. for all DLEs (I think that's the correct term) the tapes
that hold that image back to the most recent level 0, inclusive.

Is there such a command that'll spit out a neat summary, otherwise where
should I be looking for the data that'll tell me this so I can write such a
tool?

--
jaq < at > spacepants.org http://spacepants.org/jaq.gpg

This one time, at band camp, Jamie Wilkinson wrote:
So I'm wondering if there's a amadmin command or somesuch that we can use
that'll tell us which tapes are in the set of tapes required to do a full
restore from, i.e. for all DLEs (I think that's the correct term) the tapes
that hold that image back to the most recent level 0, inclusive.

Thanks to those people who replied privately.

I was about to write a tool to do this and I found that amadmin export's
stats field lists only those tapes that have not yet been superceded, i.e.
the latest level 0, any level 1s after that, etc, which is exactly what I
need:

/usr/sbin/amadmin foo export | grep stats | cut -f8 -d' ' | sort | uniq

--
jaq < at > spacepants.org http://spacepants.org/jaq.gpg

On Jul 15, 2004, at 9:53 PM, Jamie Wilkinson wrote:

This one time, at band camp, Jamie Wilkinson wrote:
So I'm wondering if there's a amadmin command or somesuch that we can
use
that'll tell us which tapes are in the set of tapes required to do a
full
restore from, i.e. for all DLEs (I think that's the correct term) the
tapes
that hold that image back to the most recent level 0, inclusive.



I am super grateful for those posters that follow-up with conclusions
and/or solutions... That's totally awesome.

And this is an interesting topic, too. Great question!

... I found that amadmin export's
stats field lists only those tapes that have not yet been superceded,
i.e.
the latest level 0, any level 1s after that, etc, which is exactly
what I
need:

/usr/sbin/amadmin foo export | grep stats | cut -f8 -d' ' | sort | uniq



Are we sure that this answers the question that was asked? i.e. is it
the
correct answer in limited number of cases but not all cases? Is your
test case a coincidence?

This is certainly motivating me to take a closer look at my tapes. I
thought
I could restore in much fewer tapes than what that pipeline indicates.
However, it's late and I'm tired, so I may not be grokking this.

Cheers
DK

This one time, at band camp, DK Smith wrote:
Are we sure that this answers the question that was asked? i.e. is it
the
correct answer in limited number of cases but not all cases? Is your
test case a coincidence?

Well, I'm not 100% sure. I only noticed a correlation between the output of
amadmin export and my expected results, so this all hinges on the output of
amadmin export being correct. A corollary of my finding is that an amadmin
import only ever gets the most recent tape set imported -- I've never used
amadmin import/export before so I have no idea if this is the required
behaviour.

This is certainly motivating me to take a closer look at my tapes. I
thought
I could restore in much fewer tapes than what that pipeline indicates.
However, it's late and I'm tired, so I may not be grokking this.

The question I'd asked is which tapes do we need to keep offsite in
order to have a complete set of tapes to restore any DLE in an emergency.

That's the set of tapes that contain the latest level 0, and any level 1
after that level 0, and any level 2 after that level 1, and so on, for each
DLE in the network.

In the best case, it's the last runtapes tapes, but that number can be
pushed up due to delayed dumps, and amflush runs; also tapes may be skipped
for whatever reason making a non-contiuguous list.

--
jaq < at > spacepants.org http://spacepants.org/jaq.gpg