shell script to watch for slow file syncs

syncer.sh

#! /bin/bash

# seconds between fdatasyncs
rate=1
# report any sync drift gte to this
drift_threshold=2

while true; do
    sleep ${rate}s
    mark1=`date +%s`;
    echo "hello disk" >> datafile
    sync -d ./datafile
    mark2=`date +%s`
    let "drift = mark2 - mark1"
    if [ $drift -ge $drift_threshold ]; then
        echo sync took $drift secs
        echo mark1 $(date --date=@${mark1})
        echo mark2 $(date --date=@${mark2})
    fi
done