driftfile writing is causing un-nessasiraly load on flash disk

[rick]

/usr/local/bin/write_ntpdrift is mounting before even the needs to be mounting. Should be something like this

#!/bin/sh
# Back-up ntp.drift file changes to flash. 

SRC="/var/db/ntp.drift"
DST="/cfg/local/ntp.drift"

EX_OK=1
EX_NOINPUT=66
EX_CANTCREAT=73

# Check whether source exists
if [ ! -r $SRC ]; then
    echo "ERROR: '$SRC' not readable!" 1>&2
    exit $EX_NOINPUT

# Check whether target is writable
if [ ! -w $DST ]; then
    echo "ERROR: '$DST' not writable!" 1>&2
    exit $EX_CANTCREAT
fi



exit $EX_OK

[tim]

Rick,

Thanks for the update. I understand your point about the flash disk getting
mounted unnecessarily, but in the example above i don`t quite get the point
where you compare the source and destination file for changes. At the moment
that the file differences are being checked, the destination is not yet
available right ?

[rick]

You are right, part

# Compare files, ignore white spaces, modification, etc
diff -b -B -q ${SRC} ${DST}
if [ $? -eq 1 ]; then
  #XXX: When is disks is already mounted for some reason (other process, script call, make sure to keep it's previous state
  mount -uwo noatime /cfg
  cp ${SRC} ${DST}
  umount /cfg
fi

needs to include extra check on non existence

# Compare files, ignore white spaces, modification, etc
diff -b -B -q ${SRC} ${DST}; RETVAL=$?
if [ [ $RETVAL -ne 0 ]; then
  #2: DST does not yet, exists, 1: file differs
  #XXX: When is disks is already mounted for some reason (other process, script call, make sure to keep it's previous state
  mount -uwo noatime /cfg
  cp ${SRC} ${DST}
  umount /cfg
fi

[rick]

(In [6908]) fixes #14, altough script has not been tested live