Merging a set of tapes when a tape is missing? 1

[Yrrk]

Does anyone know for sure if you can do anything about the following scenario.. Lets say you have 10 tapes that are a set from one night's backup. They are sequence 1 through 10. For some reason, tape #7 is missing or damaged and you've lost your arcserve database. So it's merge time!

If you put sequence 1 in and merge, it will happily ask for tapes 1-6 until you get to 7 and realize you have to cancel your merge because you're missing that tape.

Is there any way to merge and restore any data on tapes 8-10?

 

[davidmichel]

A merge always has to start at the begining of a session.

So the question is where the session begins and ends. If you have one session that goes from the seq. #1 tape all the way to # 10, it is time for the data recovery service.

If there is a session that begins on #8 then that session can be merged.

 

[Yrrk]

what if the second session starts on 9? do you start merging 9? or would merging 8 pick it up?

 

[speshalyst]

HI,

You can restore data from tapes 8-10 using "Restore by Backup media", which does not use the ARCserve database.


Cheers
Speshalyst

So it Shall be Written!
So it Shall be Done!!

 

[davidmichel]

If Session # 2 starts on tape seq. # 9 then load tape #9 to merge and restore from session # 2.

Restore by Media can not restore from the middle of a session, it must start at the begining of the session.

Since tape seq. # 8 is in the middle of session # 1 there is no point in loading it.

 

[Yrrk]

I see.. so if someone were to hand you a set of 10 tapes, except sequence #7 was missing (you only had 9 of them), you'd have a problem. You probably wouldn't know how many sessions were on the set of tapes nor what tape they began or ended on. So to get as much as possible off the tapes you would..

1. merge sequence 1.. when it asks for #7 you have to cancel.
2. merge sequence 8
3. merge sequence 9
4. merge sequence 10

now you should've caught everything?

 

[elanor]

Well, you could use the Scan function to scan the media for information about your sessions.
Thanks!
Elanor

 

[davidmichel]

Yes in that case Scan would be a good first step.

Load tape 1 and run a Scan all sessions job. The job will fail at the missing tape. So you would setup a new Scan job with tape 8 loaded. In this case it would find nothing and request tape 9 where it would find session # 2, and so on.

The job log will tell you the sessions, and the server and volume each session contains.

 

[Yrrk]

I just ran a merge of a set of tapes where I was missing sequence 7. Naturally, when it asked for sequence 7, I had to hit cancel since I didn't have it. But afterwards, when poking around the restore view and database view, I see 15 sessions across thos first 6 tapes and none of them seem to have any info other then very high level.

In other words, I can see it was a backup of some server's C drive and that there are X number of bytes and Y number of files. But I can't drill down into the session and actually see the files or directories. It's like it didn't comitt the merged info into the database.

Is this due to my hitting cancel?

Is there a way to merge the first 6 tapes such that I *can* see the data?

Thanks!

 

[davidmichel]

All but the last session should have been merged.

At the end of each session there is a catalog file containing all the database information. That file the last file in each session and is restored and then the contents merged. So as the merge job was running the data from all the earlier sessions should have been merged in.

The last session is the exception since it was not completed. Actually there is a registry hack to get it to do an old style merge.

Open regidt32.exe
Go to HKEY_LOCAL_MACHINE on Local Machine
Open it to
HKEY_LOCAL_MACHINE\SOFTWARE\ComputerAssociates\ARCserveIT\Base\Task
Highlight Task and select Edit Add Key from the menue bar.
Key Name: Merge
Class: <leave blank>
Hightlight Merge and select Edit Add Value
Value Name: DonotUseCatalogMerge
Data Type: REG_DWORD
click OK
Data: 1 *// 1 = Enabled, 0 = Disabled

Also now would be a good time to update. You might also consider database corruption.