🚀 go-pugleaf

In article <1gkvvfINN66@menudo.uh.edu> sears@tree.egr.uh.edu (Paul S.
Sears) writes: ...

   In article <1992Dec9.101922.618@nexcom.hanse.de> helmut@nexcom.hanse.de  
   (Helmut Schoenborn) writes: ...
   #I receive
   #
   #	Tape/disk read error: I/O error

   ... I think this is because your drive is not set to fixed block mode for  
   restore which it was during dump.  What I do, and this has ALWAYS worked,  
   is a 

   localhost:4# restore i
   /dev/rxt0: I/O error

   Then I do a

   localhost:5# restore if /dev/nrst0

   and the restore works just fine.  The default device for tape is /dev/rxt0  
   which, if I remember correctly, is a exabyte device which uses a fixed  
   block length....

This very common problem isn't fixed vs. variable block length mode,
per se, but "allow illegal length" vs. "inhibit illegal length".
Sear's workaround is a ineligant but functional way of getting the
"allow illegal length" mode set.  A cleaner way is to compile the
following and call the executable mtalill.  Then do "mtalill
/dev/nrst0" before your restore.  (I do it in the /etc/rc.local every
time the machine boots.)

#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <nextdev/scsireg.h>
#include <sys/file.h>

main(int argc, char *argv[]){
  int fd;

  if(argc != 2){
    fprintf(stderr, "Usage: %s device\n", argv[0]);
    exit(1);
    }

  if((fd = open(argv[1], O_RDONLY, 0)) < 0){
    perror(argv[1]);
    exit(1);
  }

  if(ioctl(fd, MTIOCALILL, NULL) < 0){
    perror("doing MTIOCALILL ioctl");
    exit(1);
  }

  if(close(fd) < 0){
    perror("closing");
    exit(1);
  }

  exit(0);
}