#! /bin/sh
###############################################################################
# AMANDA Tape Changer script for use with the MTX tape changer program
# Version 1.0 - Tue Feb 20 13:59:39 CST 2001
#
# Based on 'stc-changer' by Eric Berggren (eric@ee.pdx.edu)
# Updated by Tim Skirvin (tskirvin@ks.uiuc.edu)
#
# Given that there's no license...let's make this the Perl Artistic License.
# Just make sure you give me and Eric credit if you modify this.
###############################################################################
### USER CONFIGURATION
# Name of the tape drive (takes place of "tapedev" option in amanda.conf)
# and default driver number in library (usu 0) that DRIVE_NAME points to
DRIVE_NAME="/dev/rmt/0n"
DRIVE_NUM=0
# Location of "STC" command and control device
MTX_CMD="/usr/local/sbin/mtx";
MTX_CONTROL="/dev/scsi/changer/c4t1d0";
# Whether tape drive must eject tape before changer retrieves
# (ie, EXB-2x0). Usually okay if set while not necessary, bad if
# required but not set.
DRIVE_MUST_EJECT=1
# How long to check drive readiness (in seconds) after mounting (or
# ejecting) a volume (on some libraries, the motion or eject command may
# complete before the drive has the volume fully mounted and online,
# or ready for retrieval, resulting in "Drive not ready"/"Media not
# ready" errors). Do an "mt status" command every 5 seconds upto this
# time.
DRIVE_READY_TIME_MAX=120
# tape "mt" command location...
MT_CMD="/usr/bin/mt" # called via "MT_CMD -f DRIVE_NAME rewind" &
# "MT_CMD -f DRIVE_NAME offline" to eject
# and "MT_CMD -f DRIVE_NAME status" to get ready info
##############################################################################
#
NumDrives=-1
NumSlots=-1
LastSlot=-1
LoadedTape=-1
#
# Usage information
#
usage()
{
echo
echo "Usage: $Progname <command> [arg...]"
echo " -info reports capability and loaded tape"
echo " -slot <slot> loads specified tape into drive"
echo " current reports current mounted tape"
echo " next loads logically next tape (loops to top)"
echo " prev loads logically previous tape (loops to bot)"
echo " first loads first tape"
echo " last loads last tape"
echo " 0..99 loads tape from specified slot#"
echo " -eject uloads current mounted tape"
echo " -reset resets changer (and drive); loads first tape"
echo
exit 5
}
#
# Perform "stc" changer command (& handle the "fatal" errors)
# else, set 'CommandResStr' and 'CommandRawResStr' to the result string
# and 'CommandResCode' to the exit code
#
dotapecmd()
{
cmd=$1
arg=$2
CommandResStr=`$MTX_CMD $MTX_CONTROL $cmd $arg 2>&1`
CommandRawResStr=$CommandResStr
CommandResCode=$?
CommandResStr=`echo $CommandResStr | head -1 | sed 's/^[^:]*: //'`
if [ $CommandResCode -gt 1 ]; then
echo "0 $Progname: returned $CommandResStr"
exit 2
fi
}
#
# Unload tape from drive (a drive command; "ejecttape" is a changer command
# to actually retrieve the tape). Needed by some changers (controlled by
# setting "DRIVE_MUST_EJECT")
#
ejectdrive()
{
# Tell drive to eject tape before changer retrieves; req'd by some
# drives (ie, EXB-2x0). Not needed by QDLT-4x00. Do a "rewind"
# command first, then "offline" to eject (instead of "rewoffl")
#
if [ "$DRIVE_MUST_EJECT" -ne 0 ]; then
mtresstr=`$MT_CMD -f $DRIVE_NAME rewind 2>&1`
mtrescode=$?
if [ $mtrescode -ne 0 ]; then
if echo "$mtresstr" | egrep -s 'no tape'; then
:; # no tape mounted; assume okay...
else
# can't eject tape, bad; output: <tape#> reason
echo "0 $mtresstr"
exit 1
fi
else
mtresstr=`$MT_CMD -f $DRIVE_NAME offline 2>&1`
mtrescode=$?
checkdrive 1
fi
fi
}
#
# Check drive readiness after (un)mounting a volume (which may take a while
# after the volume change command completes)
#
checkdrive()
{
unmounting=$1
if [ "$DRIVE_READY_TIME_MAX" -gt 0 ]; then
# sleep time between checks
pausetime=5
# number of interations to check
numchecks=`expr $DRIVE_READY_TIME_MAX / $pausetime`
if [ "$numchecks" -eq 0 ]; then
numchecks=1
fi
# check until success, or out of attempts...
while [ "$numchecks" -gt 0 ]; do
mtresstr=`$MT_CMD -f $DRIVE_NAME status 2>&1`
mtrescode=$?
if [ $mtrescode -eq 0 ]; then
# Success ?
return 0
else
# pause, before trying again....
if [ "$numchecks" -gt 1 ]; then
sleep $pausetime
# if unmounting a volume, check for 'mt' command
# failure; (sleep first for additional comfort)
if [ "$unmounting" -ne 0 ]; then
return 0
fi
fi
fi
numchecks=`expr $numchecks - 1`
done
# failed; output: -1 reason
echo "-1 drive won't report ready"
exit 1
fi
}
#
# Get changer parameters
#
getchangerparms()
{
dotapecmd status
if [ $CommandResCode -eq 0 ] && \
echo "$CommandResStr" | egrep -s '^Storage Changer'; then
NumDrives=`echo $dspec | wc -l`
NumDrives=`echo "$CommandRawResStr" | \
grep 'Data Transfer Element' | wc -l`
if [ "$NumDrives" -le "$DRIVE_NUM" ]; then
echo "$Program: Invalid drive # specified ($DRIVE_NUM > $NumDrives)"
exit 3
fi
# grep 'Data Transfer Element $DRIVE_NUM' | \
LoadedTape=`echo "$CommandRawResStr" | \
grep 'Data Transfer Element' | \
grep 'Storage Element [0-9]' | \
awk '{ print $7 }' `
if [ -z "$LoadedTape" -o "$LoadedTape" = "e" ]; then
LoadedTape=-1
fi
NumSlots=`echo "$CommandRawResStr" | \
grep 'Storage Element [0-9]\{1,\}:' | \
grep -v 'Data Element' | \
wc -l | sed -e 's/ //g' `
LastSlot=`expr $NumSlots - 1`
else
echo \
"$Progname: Can't get changer parameters; Result was $CommandResStr"
exit 3
fi
}
#
# Display changer info
#
changerinfo()
{
getchangerparms
# output status string: currenttape numslots randomaccess?
echo "$LoadedTape $NumSlots 1"
exit 0
}
#
# Eject current mounted tape
#
ejecttape()
{
getchangerparms
ct=$LoadedTape
# If no tape reported mounted, assume success (could be bad if changer
# lost track of tape)
#
if [ $ct -lt 0 ]; then
CommandResCode=0
else
ejectdrive
dotapecmd unload
fi
if [ $CommandResCode -ne 0 ]; then
# failed; output: <tape#> reason
echo "$ct $CommandResStr"
exit 1
else
# success; output: <tape#> drive
echo "$ct $DRIVE_NAME"
exit 0
fi
}
#
# Move specified tape into drive (operation level)
#
doloadtape()
{
slot=$1
if [ "$slot" -eq "$LoadedTape" ]; then
return 0
fi
ejectdrive
dotapecmd load $slot
return $CommandResCode
}
#
# Load next available tape into drive
#
loadnexttape()
{
curslot=$1
direction=$2
startslot=$curslot
while true; do
if doloadtape $curslot; then
return 0
else
if echo $CommandResStr | egrep -s 'Slot.*reported empty'; then
if [ "$direction" -lt 0 ]; then
curslot=`expr $curslot - 1`
if [ "$curslot" -lt 0 ]; then
curslot=$LastSlot
fi
else
curslot=`expr $curslot + 1`
if [ "$curslot" -gt "$LastSlot" ]; then
curslot=0
fi
fi
# Check if we're back to where we started...
if [ "$curslot" = "$startslot" ]; then
if [ "$direction" -lt 0 ]; then
CommandResStr="No previous volume available"
else
CommandResStr="No subsequent volume available"
fi
return 1
fi
else
return 1
fi
fi
done
}
#
# Report loadtape() status
#
reportstatus()
{
if [ $CommandResCode -eq 0 ]; then
# success; output currenttape drivename
echo "$LoadedTape $DRIVE_NAME"
exit 0
else
# failed (empty slot?); output currenttape reason
echo "$LoadedTape $CommandResStr"
exit 1
fi
}
#
# Move specified tape into drive (command level)
#
loadtape()
{
slot=$1
getchangerparms
case "$slot" in
current)
if [ $LoadedTape -lt 0 ]; then
CommandResStr="Can't determine current tape; drive empty ?"
CommandResCode=1
fi
;;
prev)
if [ $LoadedTape -le 0 ]; then
loadnexttape $LastSlot -1
else
loadnexttape `expr $LoadedTape - 1` -1
fi
;;
next)
if [ $LoadedTape -ge $LastSlot -o $LoadedTape -lt 0 ]; then
loadnexttape 0 1
else
loadnexttape `expr $LoadedTape + 1` 1
fi
;;
first)
loadnexttape 0 1
;;
last)
loadnexttape $LastSlot -1
;;
[0-9]*)
doloadtape $slot
;;
*)
# error; no valid slot specified
echo "$Progname: No valid slot specified"
exit 1
;;
esac
if [ $CommandResCode -eq 0 ]; then
getchangerparms
checkdrive
fi
reportstatus
}
#
# Reset changer to known state
#
resetchanger()
{
ejectdrive
dotapecmd reset
if [ $CommandResCode -ne 0 ]; then
# failed; output: failed? reason
echo "-1 $CommandResStr"
exit 2;
else
loadtape first
fi
}
#############################################################################
#
# MAIN
#
Progname=`basename $0`
if [ ! -x "$MTX_CMD" ]; then
echo "-1 $Progname: cannot run STC command ($MTX_CMD)"
exit 2
fi
if [ -n "$MTX_CONTROL" ]; then
if echo "$MTX_CONTROL" | egrep -s '^-f'; then
:;
else
MTX_CONTROL="-f $MTX_CONTROL"
fi
fi
if [ -n "$DRIVE_NUM" ]; then
DRIVE_NUM=0
fi
if [ $# -ge 1 ]; then command=$1; else command="-usage"; fi
case "$command" in
-info)
changerinfo
;;
-slot)
loadtape $2
;;
-eject)
ejecttape
;;
-reset)
resetchanger
;;
*)
usage
;;
esac
exit 0
