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Do I need to turn off my server to replace a SCSI cable for an external tape drive?

sliknick1028 asked
Medium Priority
Last Modified: 2013-11-14
Server 2003 R2
I have an HP StorageWorks Ultrium 215 external tape drive connected via SCSI cable to an external SCSI adapter.  Everything was working fine for awhile until the backup failed 1 day.  I was able to get it back up and running by powering off the Tape drive, disconnecting the SCSI cable from the tape drive, and disconnecting the power... then plugging everything back in.  Then after about a week it stopped again.  After some troubleshooting we decided to replace the SCSI cable which leads to my simple question.  
Do I need to turn off my server or can I just swap out the SCSI cable with everything on (obviously I'll power off the tape drive).
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I hot-swap SCSI devices all the time without ill effect so you shouldn't have any problem doing this.

BTW - As for your backup failing... is the tape old? Have you run a cleaning tape cycle?

However... if there is a problem with the old cable, it might be worth power-cycling the server so that the host adapter 'sees' the new cable.
Sai Prasad KinneraManager, Technical Support

power cycle needs to be done so that host adapter finds the drive, i have seen issues where if power cycle is not done and when i do scan for hardware changes for eg: tape autoloader i either see a changer or a tape drive or i dont see any thing.. so itz better to perform power cycle when ever it is removed.


Well I got the correct cable but the metal part of the HD68 male connector was not deep enough so it wouldn't stay on and the screws wouldn't screw in... so much for going with the cheaper cable.  So I kept the old SCSI cable connected but had to reboot and go into the SCSI configuration and scan for the device.  It recognized the tape drive but now when I try to do a backup in ArcServ I get error message "E3855 Unable to position media... EC= Unrecoverable data error" and the backup fails.  What do you suggest?
OK. That's very unlikely to be anything to do with the cable. "EC" almost certainly stands for ECC, which is an error recovery algorithm applied at at the media level.

You've either got a bad tape (solution: replace); dirty tape head (solution: run cleaning tape); or, defunct drive (solution: get supplier to swap if still under warranty, or, if not, time to buy another drive)

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Well, the old SCSI cable seems to be fine.  I just sent a cleaner tape through the tape drive and swapped out the tape with a new one and it has been about a week with the backup jobs successfully running.  Thanks for all your help!
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