> 27/04/2006 18:40:54 - positioning 0622L3 to file 87
> 27/04/2006 18:42:14 - Warning bptm(pid=3888) cannot locate on 
> drive index 0,
> The request could not be performed because of an I/O device error. 
> 27/04/2006 18:42:18 - Error bptm(pid=3888) ioctl (MTREW) 
> failed on media id
> 0622L3, drive index 0, The device is not ready. (21) (bptm.c.6355)
> 27/04/2006 18:42:19 - Error bptm(pid=3888) ioctl (MTREW) 
> failed on media id
> 0622L3, drive index 0, The device is not ready. (21) (bptm.c.6612)
> 27/04/2006 18:42:20 - Warning bptm(pid=3888) FREEZING media 
> id 0622L3, it
> has had at least 3 errors in the last 12 hour(s)
> 27/04/2006 18:42:27 - end writing
> media position error(86)
> media position error(86)
> 27/04/2006 18:42:32 - Error bpsched(pid=5656) backup of 
> client 194.35.68.209
> exited with status 86 (media position error)

[snipping irrelevant parts about job retry success]

> Normally I would not be worried, but what does bother me is 
> the message about device is not ready, when in fact the
> drives are up, no errors are reported in the event logs.

The logs didn't say the drive wasn't up.  "cannot locate... I/O device
error... device is not ready..."  The drive wasn't ready when the
rewinds were issued.  Don't overthink this--you had a basic media or
hardware problem.  You know the tape, the drive and the connections.
Test, fix, drive on.  /usr/openv/netbackup/bin/admincmd/bperror -S 86 -r