how to create /dev/st0 in redhat enterprise 4

[Nigel Wade]

Khalid wrote:
> hi
> i have created /dev/st0 for SCSI tape drive in redhat enterprise 4 from
> mknod -m 660 /dev/st0 c 9 0
> but when i start backup using tar
> (tar -cvf /dev/st0 /boot /home)
> it is showing error No such file or directory
> 
> thanks
> 

You should not be creating /dev/stX entries. The st kernel module ought to 
create those when it is loaded. When the SCSI driver for your SCSI card loads it 
will scan the SCSI bus, and you should see info in /var/log/dmesg about what 
devices it found. When st loads you should see an entry for each tape device it 
finds, and it will create the /dev/stX entries for them. If the st driver 
doesn't find your SCSI tape drive, creating an entry in /dev won't help, as the 
st driver still won't communicate with your drive.

Check that the st kernel module is loaded. Look for something like this in the 
output of lsmod:

st                     42085  0
scsi_mod              140177  6 st,sg,qla2xxx,scsi_transport_fc,mptscsih,sd_mod


See what messages are in dmesg log regarding your tape drive. You should have 
entries like these below.

This is a tape device being identified by the SCSI device driver:

  scsi5 : ioc5: LSI53C1030, FwRev=01032700h, Ports=1, MaxQ=203, IRQ=98
    Vendor: HP        Model: C5683A            Rev: C908
    Type:   Sequential-Access                  ANSI SCSI revision: 02


The generic scsi kernel module creates an entry for it:

  Attached scsi generic sg7 at scsi5, channel 0, id 1, lun 0,  type 1


The st module creates an entry for it:

  Attached scsi tape st2 at scsi5, channel 0, id 1, lun 0
  st2: try direct i/o: yes (alignment 512 B), max page reachable by HBA 4194304

-- 
Nigel Wade, System Administrator, Space Plasma Physics Group,
             University of Leicester, Leicester, LE1 7RH, UK
E-mail :    nmw at ion.le.ac.uk
Phone :     +44 (0)116 2523548, Fax : +44 (0)116 2523555