Networker

Re: [Networker] hypothetical question

2011-01-21 12:25:56
Subject: Re: [Networker] hypothetical question
From: Ken Gehring <ken.gehring AT GMAIL DOT COM>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Fri, 21 Jan 2011 10:23:56 -0700
We also use rsync to keep a backup copy of /nsr on the Networker
server. We use HP-UX and NW 7.5.3.2. We schedule it as a cron job and
run it every 30 min. When we do an upgrade we disable the cron entry,
remove all tapes with any data on them from the library, shut down
networker and run the rsync command from the console. The we unmount
the backup copy (and comment out the entry in fstab). Then we proceed
with upgrade. So far we've been able to back up very well when things
went south for us (don't ask) by using the backup copy of /nsr. We
just need to keep track of tapes that will need to be relabeled from a
failed upgrade/test.

Here is the rsync entry in crontab (no -S option)

/usr/local/bin/rsync --delete -aue /nsr/* /nsrback > /dev/null

Hope this helps.

Ken

2011/1/21 Valere Binet <valere.binet AT gmail DOT com>:
> We did the first transfer with star and run rsync once a day.
> I wrote "hoping" because we didn't test the promotion of a storage node to
> server ... yet.
> We have NetWorker 7.4.4-1 on all our systems. The server and storage nodes
> are running CentOS 5.5.
>
> From this conversation, it seems our strategy could be doomed to fail
> because :
> 1) rsync runs on a live server (we don't shutdown nsr)
> 2) we don't use the -S option
>
> Right?
>
> Maybe it is time to rethink the whole process and find a way to test it.
> I'll keep you posted.
>
> Valere
>
> On Thu, Jan 20, 2011 at 5:01 PM, George Sinclair
> <George.Sinclair AT noaa DOT gov>wrote:
>
>> Valere Binet wrote:
>>
>>> We rsync /nsr to one of our storage nodes, hoping we can "promote" it
>>> should
>>> our server die.
>>>
>>
>> Do you use the '-S, --sparse' options with rsync?
>>
>>
>>> Valčre
>>>
>>>
>>> On Thu, Jan 20, 2011 at 2:15 PM, Tim Mooney <Tim.Mooney AT ndsu DOT edu> 
>>> wrote:
>>>
>>>  In regard to: [Networker] hypothetical question, helenjay said (at
>>>> 7:41am...:
>>>>
>>>>
>>>>  If I tar'd the whole of /nsr and anything else related to networker,
>>>>
>>>>> could I use that backup to recover networker as opposed to mmrecov and
>>>>> scanner etc., should I have a major disaster?
>>>>>
>>>>>  In the old, old days, the answer would likely have been "no", because
>>>> many
>>>> versions of tar did not preserve sparse files and some of the db files
>>>> had
>>>> the potential to be sparse.
>>>>
>>>> These days, that's less of a concern.  More versions of tar handle sparse
>>>> files, and the changes to the database formats have reduced or possibly
>>>> even eliminated the chance that any of the files will be sparse.  You
>>>> don't say what platform you're on, so you'll want to check your version
>>>> of
>>>> tar to make certain it does preserve sparse files, just in case.
>>>>
>>>
>> We've tarred /nsr off to a safe location a few times in the past, with NW
>> shut down, but it didn't occur to me to use the 'sparse' option with tar
>> even though GNU tar does support it. However, I always created an MD5
>> checksum listing of all of /nsr (recursive) before creating the tar archive
>> and then tested the archive by untarring it and validating all the sums. I
>> don't know if NW might use sparse files, but I guess it couldn't hurt to
>> include the option when using tar.
>>
>> 1. If NW does use sparse files, or did, what would happen if you didn't
>> include the option with tar? What's the worst case?
>>
>> 2. If you shut down NW, create MD5 checksums for all the files under /nsr
>> before tarring them, and then you create your tar file without the 'sparse'
>> option, and you then untar the archive somewhere else and validate all the
>> checksums, and everything matches then is it safe to say there are no sparse
>> files?
>>
>> If there were sparse files, and you didn't include the option with tar then
>> would you expect to see a mismatch on the MD5 sums for those files?
>>
>> George
>>
>>
>>
>>>> If the db files are quiescent (i.e. NetWorker shut down, or no checking
>>>> or updating going on for the files), a tar copy of them should be fine.
>>>> I wouldn't want it to be my only backup method, but it's a useful
>>>> addition
>>>> to the standard bootstrap DR procedure.
>>>>
>>>> Tim
>>>> --
>>>> Tim Mooney
>>>> Tim.Mooney AT ndsu DOT edu
>>>> Enterprise Computing & Infrastructure                  701-231-1076
>>>> (Voice)
>>>> Room 242-J6, IACC Building                             701-231-8541 (Fax)
>>>> North Dakota State University, Fargo, ND 58105-5164
>>>>
>>>>
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>>>>
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>>>
>>
>>
>> --
>> George Sinclair
>> Voice: (301) 713-3284 x210
>> - The preceding message is personal and does not reflect any official or
>> unofficial position of the United States Department of Commerce -
>> - Any opinions expressed in this message are NOT those of the US Govt. -
>>
>>
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>
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