Restoring Data from DAT72 to DDS4 tapes
Hi Guys, I have 2 servers
1.IBM System x3650 with Dat72 Tape drive
2. IBM xSeries 235 Server with DDS-4 Tape drive
i'm using DDS-4 tapes to be supported by both of them
the problem is i can make a backup on the dds-4 tape from the DAT72 Tape drive with no problem but i can't restore it on the DDS-4 Tape drive which shows that the tape is empty but i checked it on the DAT72 Tape drive and i found the data there....
both of these servers are running windows Server 2003 Enterprise Edition , i can't find any special settings to try n error in the device manager
can anyone tell me what iam missing to make this work for both servers.
1.IBM System x3650 with Dat72 Tape drive
2. IBM xSeries 235 Server with DDS-4 Tape drive
i'm using DDS-4 tapes to be supported by both of them
the problem is i can make a backup on the dds-4 tape from the DAT72 Tape drive with no problem but i can't restore it on the DDS-4 Tape drive which shows that the tape is empty but i checked it on the DAT72 Tape drive and i found the data there....
both of these servers are running windows Server 2003 Enterprise Edition , i can't find any special settings to try n error in the device manager
can anyone tell me what iam missing to make this work for both servers.
Here's why the tapes written on the DAT 72 can't be read by the DDS-4:
"DAT-72 tapes are 170m long and data is written in narrower tracks, again increasing data density, enabling tapes to hold 80% more data than DDS-4 tapes. " - the emphasis is mine.
(from http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50457&locale=en_US&taskId=101&prodSeriesId=81997&prodTypeId=12169)
In short, tapes written on the DDS4 can be read on the DAT72, but not vice-versa. Wikipedia has this to say: "Backward compatibility between newer drives and older tapes is not assured." (http://en.wikipedia.org/wiki/DDS-4)
So - this behaviour is expected. The tapes DDS-4 tapes written by the DAT72 drive can't be read on the DDS-4 drive
"DAT-72 tapes are 170m long and data is written in narrower tracks, again increasing data density, enabling tapes to hold 80% more data than DDS-4 tapes. " - the emphasis is mine.
(from http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50457&locale=en_US&taskId=101&prodSeriesId=81997&prodTypeId=12169)
In short, tapes written on the DDS4 can be read on the DAT72, but not vice-versa. Wikipedia has this to say: "Backward compatibility between newer drives and older tapes is not assured." (http://en.wikipedia.org/wiki/DDS-4)
So - this behaviour is expected. The tapes DDS-4 tapes written by the DAT72 drive can't be read on the DDS-4 drive
ASKER
I'm using Windows NTBackup on both servers .... is there an advanced Configurations menu somewhere?
i can't find any thing about that "tape offset setting"
i can't find any thing about that "tape offset setting"
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ASKER
So isn't there any way to make this work in windows .... i faced the same problem with the same devices but on IBM AIX 5.2 system but it has been solved by changing Block-size & Density parameters
ASKER
i found out that only a portion of the backed-up data was readable on the IBM AIX 5.1 ... so i'll try and change the Tape Drive with another DAT72 Drive
Thanks! Glad I could help.
it could sound from your problem description that the tape offset setting of the drives are different.
Try to see if you can find this/such setting on the '1' and set accordingly on your '2'.
I do assume you're using the same backup/restore software on '1' and '2'?
Kind regards,
Soren