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wrong version - content unrecognized

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Some months ago I upgraded our backup server from Retrospect 5.5 Windows Server 100 users to 6.0 Multiple Server. At the same time I switched from DDS-4 to LTO, creating new backup scripts and everything.


I had not used the DDS drive for a while, but now, when insert one of the tapes created by 5.5 the 'Storage Devices' window displays "Wrong Version" for a second, then displays "Unrecognized Content". Can this be? And, if yes, can I install V5.5 parallel to 6.0?


I have cleaned the drive, but to no avail.


Thanks :-)

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Content unrecognized is usually a result of the tape drive not being able to read or recognize the header information on a tape usually due to problems with the tape or tape drive. However, there are two exceptions. One exception to this is when tapes are written with a drive that utilizes hardware compression but in turn are used in drives that do not utilize hardware compression. Such tapes will appear as “Content unrecognized” in drives that do not have the ability to read compressed data. The other exception is when a tape was written by another utility other than Retrospect. This tape cannot then be read with Retrospect. If neither of these exceptions apply to your situation, read further.


If only the tape or tapes in which you are interested come up "content unknown/unrecognized," then the problem is isolated to the tape(s) in question. If all or many of the tapes show "content unknown/unrecognized," you may have a more general problem with the SCSI bus or SCSI device.


If it's just one set of tapes with problems, you can try to optimize your chances for recovery or catalog recreation by confirming the following items even though they are not likely to resolve the problem of a damaged tape:


1) cleaning the drive;

2) removing SCSI devices other than your tape drive from your chain;

3) making sure you are using good cables, proper termination and have solid connections between the computer, cables, tape drive and terminator.


If the tape(s) still show "content unknown/unrecognized," the last option is to contact a data recovery house. Data recovery tends to be an expensive prospect ($2000/tape, for instance). Contact Dantz again if you'd like references of tape recovery specialists.


To avoid the problem in the future, make sure you have multiple copies of your data on different sets of tapes and rotate your media from time to time. Make sure you are storing the tapes in a secure location, protected from excessive humidity, temperature, direct sunlight and electro-magnetic radiation.


If all or most of your tapes are coming up "content unknown/unrecognized," you should investigate potential problems on your SCSI bus. Such problems can be caused by one or more of the following:


1) a dirty tape drive or bad tape. Clean the drive using a 4mm cleaning cartridge. Your drive manufacturer recommends that you clean the unit once for every 8-10 hours of run time. Once a week is more than enough for most people. Try another tape. If other tapes work, then you just have a tape with a spot that's bad enough to crash your backup.


2) another device on your SCSI bus is interfering with the tape drive's communication. Make sure your SCSI ID numbers are set correctly. Turn off your Mac and the SCSI devices. Disconnect all SCSI devices except for the tape drive.


3) you have a bad cable. Replace the SCSI cable that connects the tape drive to the computer after removing other devices and cables from the SCSI chain.


4) you are missing a terminator or have a bad terminator. The last device and ONLY the last device in your SCSI chain needs to be terminated. Try replacing the terminator if you already have one on the chain.


5) the computer may be having a problem. Install Retrospect on another Macintosh and try the tape drive there as the lone SCSI device.


6) the drive may be defective. If you have implemented all of the preceeding steps and get failures on multiple tapes after changing cables, terminators and computers, then the drive, being the only factor that has not changed, is the culprit--send it back to your vendor for repairs.

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