Networker

Re: [Networker] Auto Media Management Question

2008-12-31 21:38:12
Subject: Re: [Networker] Auto Media Management Question
From: Peter Viertel <peter AT VIERTEL DOT ORG>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Thu, 1 Jan 2009 13:33:00 +1100
> I have manually loaded tapes into the I/E slots and then used nsrjb to
> move it to the storage slots.

Ok so far.

> Barcode reader is enabled for the library so there are volumes which are
> labeled with barcode # but not in the media index ( i.e. not allocated to
> any of the media pools )

What's going on here?   You say they are labeled, but not in the 'media
index', I presume you mean not in the media [database]. I also presume you
are assuming that 'labelled' means 'has a barcode on it' which is not how
the terminology works in networker.

When you label a tape in networker-speak that means a small data block is
written onto the beginning of the tape, you must specify a pool when doing
this or the pool is one called Default (this labeling is done either by
using the nsrjb or nsrmm commands). This information is written into the
label data and cannot be changed until you relabel it (and therefore
effectively erase all the data on the tape).

Now if a tape is truly blank and has no label block on it will not show up
in the media database, nsrjb will show you what the barcode reader can see
in the barcode column but the volume column will show a dash and an asterix
'-*'.

This is normal, at this stage if an inventory or a mount is tried on one of
these tapes there is nothing to read off the tape and a warning message will
be seen, in fact it will be counted as an error - if you were to keep asking
for an inventory 20 times in a row the drive may in fact get put into
service mode, but in normal operations the system will know the barcode
isn't in the media database and will not automatically try to inventory it
until another operation chooses the tape.

> 
> I was expecting networker to pickup and label any of those tapes.
>

This would be normal, as nothing will actually happen until a tape is needed
for a write operation, it doesn't go off and immediately take the time and
effort of labeling all the blank tapes - given that you don't know in
advance what pool may be needed, pre-labelling isn't strictly necessary -
although there's something to be gained by pre-labelling as it can identify
unwriteable (wrong media type, write protected) volumes during the daytime
instead of in the middle of the night for example.  Some of us on this list
prefer to pre-label into a scratch pool, others prefer to switch on auto
media management where the labeling only occurs when needed.

Now if you have the 'Auto Media Management' setting set to Yes on this
jukebox and there is a demand for a writeable tape, and there are no
half-full tapes in the right pool, and there are no tapes marked as
recyclable, OR if the pool configurations do not allow the recycling of
tapes into the requested pool then AMM allows the system to choose one of
the blank tapes and try to label it.

> Finally I added the tape  when error came up

Ok - I'm thinking here that your problem is that you have tapes that were
labeled on another system already, or you've actually deleted the volumes
from the media database using 'nsrmm -d'. If you look through the daemon.log
from the time when you loaded the tapes until the time where you see that
message it may be that it's tried loading each tape - discovered it's not
really blank, and then discounted it from further operations, networker
doesn't know if your tape has data that should be retained and errs on the
side of caution.

If you do have this problem then you need to manually choose to relabel all
of these tapes by hand - the recommended approach is to create a pool called
'Scratch' make sure that this pool is configured to allow its tapes to be
recycled into other pools, and use the gui or the nsrjb command to label all
of the tapes into Scratch, then mark all of these tapes as recyclable.

It's recommended you do not mix tapes from one networker zone with another -
keep then separate - use different barcode ranges to do this, if you only
load blank or known tapes you will not have this problem.

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