A workaround for Overland 2000 tape devices (via FC), /dev/sgx, /dev/nstx not being added automatically in RHEL4. This was my first python script, so feel free to LoL

qla-add-tapedrives

#!/usr/bin/env python
#This is a workaround for Overland 2000 tape devices (via FC), /dev/sgx, /dev/nstx not being added automatically in RHEL4.
#For more information see notes at end of file
#
# chkconfig: 235 71 25 
# description: Workaround for Overland 2000 tape devices (via FC) \
#              being added as device nodes.
DEBUG = 9
import os, re, time
qla_search_path = '/proc/scsi/qla2xxx'
scsi_file = '/proc/scsi/scsi'
qla_hba_file = ''
IDLunArray = {}
for qlafile in os.listdir(qla_search_path):
  try:
    f = open(qla_search_path + '/' + qlafile, 'r+')
    for line in f.readlines():
      HBAMatch = re.match('QLogic PCI to Fibre Channel Host Adapter(.*) ' , line)
      IDLUNMatch = re.match('^\(\s(\d):\s(\d)\)', line)
      if HBAMatch:
        qla_hba_file = f.name.split('/').pop();
        if DEBUG:
          print 'found QLA controller id: ' + qla_hba_file
        try:
          f.write("scsi-qlascan\n")
          time.sleep(3)
        except:
          print "Could not write to file: " + qlafile
      elif IDLUNMatch:
        try:
          if IDLunArray[IDLUNMatch.group(1)] :
            if DEBUG:
              print "Matched Regular expression for ID:" + IDLUNMatch.group(1) + " LUN:" + IDLUNMatch.group(2)
            IDLunArray[IDLUNMatch.group(1)].append( IDLUNMatch.group(2) )
        except KeyError:
          if DEBUG:
            print IDLUNMatch.group(1) + " not found in IDLunArray, adding it."
          IDLunArray[IDLUNMatch.group(1)] = []
          IDLunArray[IDLUNMatch.group(1)].append( IDLUNMatch.group(2) )
  except IOError:
    print "Could not open/read file:" + qlafile

for ID in (IDLunArray):
  for LUN in IDLunArray[ID]:
    #You must open/close the file handle for each line you write (flushing may be sufficient?)
    try:
      f = open(scsi_file, 'w')
    except:
      print "Could not open file: " + scsi_file
    if DEBUG:
      print "Adding scsi device: " + qla_hba_file +" with ID: " + ID + ". And LUN: " + LUN + ' to ' + f.name
    f.write('scsi add-single-device ' + qla_hba_file + ' 0 ' + ID + ' ' + LUN + "\n" )
    f.close()
if DEBUG:
  print 'done.\n';


#NOTES:
#http://publib.boulder.ibm.com/infocenter/tssfsv21/index.jsp?topic=/com.ibm.sanfs.doc/foe0_t_adding_luns_to_sanfs.html

#The following text was taken from the overland support site, before Overland expired the article:
#[6169] How to rescan devices in Linux OS without reloading the linux driver?
#Procedure:
#There is a procedure which forces the driver to rescan the targets to allow a new device to be added. This triggers the driver to initiate a LUN discovery process.
#To force a rescan from the command line, type the following command:
# echo "scsi-qlascan" > /proc/scsi//
#Where:
#- = qla2100, qla2200, qla2300 (2.4 kernel drivers) or qla2xxx (2.6 kernel drivers)
#- = the instance number of the HBA
#After executing this command, force the SCSI mid layer to do its own scan and build the device table entry for the new device by typing the following command:
# echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
#Where:
# "0 1 2 3" = your "Host Channel ID LUN"
#The scanning must be done in the above mentioned order: first the driver (qla2300/qla2200 driver, etc.), and then the Linux SCSI mid layer (i.e. OS scan).