Networker

[Networker] Advice needed about reading a "foreign" bootstrap

2010-07-26 21:51:52
Subject: [Networker] Advice needed about reading a "foreign" bootstrap
From: wallace88 <networker-forum AT BACKUPCENTRAL DOT COM>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Mon, 26 Jul 2010 21:48:09 -0400
> Couple years ago, my NW server crashed and burned, totally. Had to re-format 
> and reinstall. Unfortunately, I did not mmrecov from the existing bootstrap 
> tape. (yes, I was an idiot, and misunderstood what I needed to do. But what's 
> done is done). So I ended up re-creating all my clients (obviously with new 
> clientids), and I just went forward from there.
> 
> Now I need to recover from a tape made from before the old server imploded. I 
> have a bootstrap tape made from the time period I need. I even have the old 
> clientid number that I need from that old tape (I have a list of most of the 
> old clientids).
> 
> I've (sort of) done this sort of procedure before, by creating a new client 
> with the old clientID; making bogus entries in my hosts file (so NW can 
> verify the host); and running "scanner -i" on old tapes, changing browse and 
> retention times; and recovering. However, in this case, I don't know which 
> tapes have the info I want, so I can't run scanner. But I think I should be 
> able to accomplish the same thing by reading the old bootstrap tape.
> 
> Planned procedure:
> 
> 1. create client (called "OldClient"), using the old clientid I found in my 
> records.
> -- the client name in use back then is still in use, but now has adifferent 
> clientid. So I need to choose a different name --
> 
> 2. create bogus entries in hosts file (i.e., 10.254.254.250 - a range we 
> don't use)
> -- this next is the step I am unsure of --
> 
> 3. nsrck -L7 -c OldClient
> 
> I should be using the entry I just made, called "OldClient", at this point, 
> yes? This will populate all the index entries for OldClient (up until the 
> time the old bootstrap was made), yes?
> 
> Then
> 
> mminfo -avot -c "client=OldClient,savetime>start-time,savetime<end-time" -r 
> volume,ssid
> 
> -- start-time being slightly before the date I need from tape, end-time being 
> slightly later --
> 
> Then I can change the browse and retention times of the SSID I need. And I 
> can then recall the volumes I need from off-site storage, and then run a 
> recover.


If the old server's client id does not match the new server's client id, then 
step 3 will not work.   Reason is simple.  NetWorker will expect the index you 
want is owned by the client id of the current server, and savesets are owned by 
the current server's client id.

My advise is for you to leave your current production server alone. Using the 
same process for a typical disaster recovery of the NetWorker server, create a 
new NetWorker server using the same name as the old one.  To avoid a network 
conflict, either use the local host file to assign it an unused i.p. address, 
or disconnect it off the network.

Make sure that name resolution works the same way.  If the old server was known 
by it's short hostname, then in the local host file put the hostname right 
after the i.p.address. If the old server was known by it's fully qualified 
domain name, then put that right after the i.p. address.  This is critical if 
you want NetWorker to use the same client id.

Once this is done, then connect a compatible tape drive, and then recover the 
bootstrap, then recover the index.  Voila, you now have a NetWorker server that 
has all the information prior to the server crashing.  You can now access the 
media database, and find out where all the backup information is stored.



> 
> > Scanner -im: since these are foreign Tape to NW server. Does the order 
> > matter? I am not Sure with the New versions I have not done this with 
> > random Tapes. But in older version of NW the order of the tapes really 
> > matters. 
> 
> My reply: Yes, the order of scanning is (usually) important - if the savesets 
> span multiple tapes. But I am *not* running scanner here, am I? I want to run 
> nsrck -L7 to restore the bootstrap (i.e., index values) for a specific 
> client. Isn't that different from "scanner -i"? I don't know which of 20 
> tapes has the info I want, and I'm not about to run "scanner" on all of them, 
> to find which volume I need, if I have the index available as a bootstrap. 
> Isn't that what the bootstrap is for - avoiding using "scanner -i"? 


Absolutely TRUE.  Especially because savesets can span multiple volumes.  
Without the media database, there is no way to know what order the volumes were 
used unless you first scan in all the volumes, then query the media database to 
determine the order used, then scan the tapes AGAIN in the correct order.


> Actually, the client is already in the mm database. It got in there when I 
> did "scanner -i" on some older tapes, when recovering for a different older 
> client( I got entries for a lot of old clients that way, all named
> "~client-name-1", since there already was a "client-name"). So I created a 
> client with the same clientID as the client had on the old server, and now it 
> shows up as the "Old-client" name, instead of "~client-name-1".



"~client-name-1" shows up because the client id does not match the client id 
that is currently defined in NetWorker.   Similarly you can see ~volume_name 
after a scan if the volume id of the tape does not match the one in the current 
media database.


> And on the bootstrap tape I will get tomorrow, are entries for a client with 
> the same clientID as my current client "Old-ADMNCRY001" has. So all I am 
> really doing is restoring the bootstrap for what NW thinks is a valid client. 
> Even if there were no entries in the mm database for "Old-ADMNCRY001", it 
> should just create them, since it will find entries on the tape for a 
> clientID that matches that client definition. That's been my experience, 
> anyway, as I have successfully done this same procedure of creating clients 
> with the old clientID previously, and then used "scanner -i" to populate the 
> index. It's just that this time, I won't be using "scanner -i", but "nsrck L7 
> -c client".


Ohhhh Boy...  I think you are under the impression that recovering the 
bootstrap will merge the media database from backups with the one that is 
online?  Well IT DOESN'T.  nsrck -L7 merges index databases ok, but recovering 
the bootstrap replaces the current media database with what you just recovered. 
 And I'm sure you don't want to lose the information in your current backup 
server.  This is the reason what I really think you should be doing this on 
test machine.

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