Anthony Worrall wrote:

Hi

unfortunately zfsdump, or "zfs send" as it is now, does not relate to
ufsdump in any way :-(
[...]
I wrote a script to use this but I had a problem getting estimates for
the incremental snapshots.

FWIW, what I use is attached (does the list accept attachements ?)

I can not see how amrecover would not be able to restore from the
snapshot as it does not know the format used. In fact there is no way
that I know of to extract a file from the snapshot sort of recovering
the whole snapshot. This is probably not too much of a big issue as the
tape backup is only needed for disaster recover and snapshot can be used
for file recovery.

amrestore could be used with "zfs receive" to recover the snapshot.

#!/bin/pfksh
#need to use pfksh so that zfs can be run

ZFS=/usr/sbin/zfs

#Get the last argument
for FS in $@;
do
echo $FS > /dev/null
done

#Check if the filesystem is zfs or ufs
res=`$ZFS list | /usr/xpg4/bin/egrep "${FS}$"`
if [ $? -eq 0 ]; then
DEV=`echo $res | awk '{ print $1}'`
ESTIMATE=0
LEVEL="unknown"
UPDATE=0

case $1 in
*0*) LEVEL=0;;
*1*) LEVEL=1;;
*2*) LEVEL=2;;
*3*) LEVEL=3;;
*4*) LEVEL=4;;
*5*) LEVEL=5;;
*6*) LEVEL=6;;
*7*) LEVEL=7;;
*8*) LEVEL=8;;
*9*) LEVEL=9;;
*) echo level NOT specfied; exit -1;;
esac

case $1 in
*S*) ESTIMATE=1;;
esac

case $1 in
*u*) UPDATE=1;;
esac

$ZFS list -H -t snapshot | /usr/xpg4/bin/grep -q ${DEV}@0
if [ $? -eq 0 ]; then
$ZFS destroy ${DEV}@0
fi
$ZFS snapshot ${DEV}@0

# make sure all the snapshots up to $LEVEL exist
n=1
while [ $n -le $LEVEL ];
do
$ZFS list -H -t snapshot | /usr/xpg4/bin/grep -q ${DEV}@$n
if [ $? -ne 0 ]; then
LEVEL=$(( $n - 1 ))
break
fi
n=$(($n+1))
done

full=`$ZFS list -H -o refer ${DEV}@0`
#convert returned size into kilobytes
case $full in
*K) full=`echo $full | sed -e 's/K//'`;;
*M) full=`echo $full | sed -e 's/M//'`; full=$(( $full * 1024 ));;
*G) full=`echo $full | sed -e 's/G//'`; full=$(( $full * 1024 * 1024));;
esac
if [ $LEVEL -gt 0 ]; then
incr=`$ZFS list -H -o refer ${DEV}@${LEVEL}`
case $incr in
*K) incr=`echo $incr | sed -e 's/K//'`;;
*M) incr=`echo $incr | sed -e 's/M//'`; incr=$(( $incr * 1024 ));;
*G) incr=`echo $incr | sed -e 's/G//'`; incr=$(( $incr * 1024 * 1024));;
esac
size=$(( $full - $incr ))
# $full can be less than $incr if we recently removed data
# zfs send -i will no be exactly 0, but relatively small
if [ $size -lt 0 ]; then
size=0
fi
else
size=$full
fi
size=$(( $size + 16 ))
if [ $ESTIMATE == 1 ]; then
# echo "doing Estimate $DEV at level $LEVEL" >&2
size=$(( $size * 1024 ))
echo $size
$ZFS destroy ${DEV}@0
else
# echo "Dumping $DEV at level $LEVEL" >&2
if [ $LEVEL -eq 0 ]; then
$ZFS send ${DEV}@0
else
$ZFS send -i ${DEV}@${LEVEL} ${DEV}@0
fi
block=$(( $size * 2 ))
MB=$(( $size / 1024 ))
echo "DUMP: $block blocks (${MB}MB)" >&2
if [ $UPDATE -eq 1 ]; then
for snap in `$ZFS list -H -t snapshot | awk '{print $1}' | egrep 
${DEV}@"[1-9]$"`; do
n=`echo $snap | cut -f2 -d@`
if [ $n -gt $LEVEL ]; then
$ZFS destroy $snap
fi
done
n=$(( $LEVEL + 1 ))
$ZFS rename ${DEV}@0 ${DEV}@${n}
else
$ZFS destroy ${DEV}@0
fi
fi
else
/usr/lib/fs/ufs/ufsdump $*
fi