Hello All ,

We are are running our system on QNX rtos , we have a amproboard LB 700 with  compact flash as the boot disk and the 
harddisk for datalogging . 
In the middle of runnning our system the harddisk disappears , i.e df -P does not show hd1t79 , it only shows hd0t79 
(compact flash) . 
When we look in the syslog , with sloginfo -w it is filled up with these errors repeating over and over 
Jan 09 13:54:34 2 5 0 scsi_interpret_sense: SK_ILLEGAL command 5a in
databyte
Jan 09 13:54:36 2 5 0 scsi_interpret_sense: path=1, target=1, lun=0,
cam_status=c4, scsi_status=2
Jan 09 13:54:36 2 5 0 scsi_interpret_sense: error=70, sense=5, asc=2
4, ascq=0
Jan 09 13:54:36 2 5 0 scsi_interpret_sense: SK_ILLEGAL command 5a in
databyte



i gather briefly from the forums i.e means the harddisk is not detected by the driver, what i cannot see is how this is 
happening in the middle of the run .ie it starts up ok , starts logging the data and after a while ( may be 1 or 2 days)
 the above errors start showing up . When we reboot the system it comes up fine again .

Any ideas / pointers to info are highly appreciated .

Thanks & Regards
-Subra