How to completely erase tapes?

[Rickard0]

I recently took over as backup admin. I had to redo alot of the work, it didn't work well to begin with. The problem I am having is that some tapes will display 1234mb Full
These are sony SDX2-50C 50/100 tapes. I can barely get any to get to 50 gigs. I think the problem is that they had data on them and was set to expire 80 million years from now. Volumes have been deleted, clients reset and tapes relabeled. They are bar code so they get the same name. Its as if there is 'unknown' data on the tapes, and it allows some info to be written to it, then says full. Nothing I have done will fix this. Legato's answer is Install current version. I did that, nothing changed. Please help.

 

[jimbopalmer]

Hi

1) If you have Networker set to compress at the Client (a very good thing) then you will only get the raw capacity of the tapes, as the data was already compressed before the tape drive saw it.

Client compression saves network bandwidth, and so improves the server's ability to back up multiple clients at once. But it removes the redundancies in the data that the tape drive manufacturer expected to use to get more than the raw capacity of the tape.

If you measure the amout of data AT the client drive compared to the amout of data on the tape you will see it is stil compressed, just not by the tape drive.

2) If you are using unix, you may also have chosen the wrong device name for the tape drive, in Solaris I think the 'best' is /dev/rmt/Xubn where X is a number

3) if the tapes are old and have errors, Networker will stop before the end of the tape (I mark these tapes as I save them, so I never re-use them) I tried to remain child-like, all I acheived was childish.

 

[gupel]

Try to delete tape from media db, format/erase the tape with other backup software (NTbackup if you using Windows) a than relable it with Networker.

 

[jimbopalmer]

in Solaris unix the mt command has an erase option I tried to remain child-like, all I acheived was childish.

 

[cia]

Hi,

Why not use the Networker ERASE program ?
(/etc/LGTOuscsi/erase) on a UNIX box.

/Cia

 

[glpauld]

Hi,
I've tried to use the Networker erase command on a win2K server box but I can't figure out what b.t.l I should use for the -a option. The command returns "scsidev@0.1.0: No such device" errors when I use the IDs that are listed in the Networker device settings or when I use the b.t.l's from the windows device manager.
Thanks,
Paul