#!/bin/sh
# writer $1 = id; sweeps the volume with stride, logging progress
i=0
id=$1
stride=$(( (id * 37) % 13 + 1 ))
while [ ! -f /tmp/stop_race ]; do
  off=$(( (i * stride * 8 + id * 64) % 688 ))
  dd if=/dev/zero of=/dev/vinum/vol/vol bs=4k seek=$off count=1 conv=notrunc >/dev/null 2>&1
  i=$((i+1))
  echo $i > /tmp/wcount.$id 2>/dev/null
done