first archive from beginning of tape invalid using ftio comand

[YR Fu]

Hi,

I make backups to a DLT8000 drive and DLT IV cartrdiges using ftio (HP N class box running HP-UX 11.00 64 bit) as follows:

ftio -ocahpvE -B 32k /dev/rmt/1mn [filelist]bl

I observe the following every time a backup is made:
1. All archives written from the beginning of tape are unreadable.

However all archives written subsequently after the first one can be read. How and why?

2. Ftio always produce the following error messages -
ftio: error reading tape header : magic number is invalid
ftio: please mount tape 1, then hit return

- whenever I tried to view the contents of the archive. I use the following command to view the contents:
ftio -ictv -B 32k /dev/rmt/1mn

I hazard a guess as normal operating behaviour.

However, if i manually forward the tape before reading the next contents using the following command, the error does not occur.
mt -f /dev/rmt/1mn fsr 1


Many thanks for your help!!!!

Cheers,
David

[Paula J Frazer-Campbell]

Hi David

I suppose you have cleaned the tape drive and used different tapes?

Have you tried using this tape drive with another backup routine - TAR,Fbackup etc, does that work ok.

Can you read your backup using cpio ?

Just a few ideas

Paula

[YR Fu]

Hi Paula,

>I suppose you have cleaned the tape drive and >used different tapes?
Yes, new tapes and used tapes exhibut the same behavior. It's a fairly new machine.

>Have you tried using this tape drive with >another backup routine - TAR,Fbackup etc, >does that work ok.

>Can you read your backup using cpio ?
Tar and cpio works fine. Archives created by them from the beginning of tape are readable.

David

[Larry Basford]

Try a Berkley device
/dev/rmt/1mnb

it may be a head positioning problem.

check the mt man page

mt winds the tape in the requested direction (forward or backward),
stopping after the specified count EOF marks or records are passed.
If count is not specified, one is assumed. Each EOF mark counts as
one record. When winding backwards, the tape always stops at the BOT
marker, regardless of the number remaining in count.