Hi Anthony,

Thanks for providing ufsdump wrapper to handle ZFS.  When Application
API (http://wiki.zmanda.com/index.php/Application_API) is implemented
(hopefully
in the next Amanda release after 2.5), creating application plugin for snapshot
based filesystem such as ZFS will be easier.  Issue 1 will be handled
by Application
API.

Paddy


On 3/8/06, Anthony Worrall <anthony.worrall AT reading.ac DOT uk> wrote:
> Hi
>
> I have playing about with Sun's new filesystem ZFS.
>
> One of the things I wanted to do was make sure I could get amanda to
> backup zfs.
> The way the backup utility works with zfs is based on snapshots. You can
> either
> do a full bakup of a filesystem or the difference between two snapshots.
> The restore process is an all or nothing recovery of the snapshot. There
> is no
> way to recover a single file from a backup or to index the snapshot.
>
> I have hacked a script to replace ufsdump which will manage the
> snapshots and
> appropriately respond to amanda's sendsize and sendbackup requests which
> is included below.
> It requires that the amanda user has a role that can run the zfs
> command. Also the
> zfs DLE's should have indexing turned off.
>
> Here are some observations about zfs and amanda. ZFS encourages the use
> of more
> smaller filesystems at the home directory or even software package level
> as it is easy
> to grow and manage filesystems. This may have an impact on amanda in a
> couple of ways.
>
> 1. Amanda seems to be more likely to do a full backup of the filesystem
> since it is
>    small. However with many small filesystems the total amount of data
> backed up may
>    end up being larger. Currently I have only a handfull of filestesm
> with a few megabytes
>    each and amanda has only request fullbackups
>
> 2. With many filesystems managing the DLE's becomes more complex. One
> idea maybe to
>    haves the DLE's for a client stored on the client. Amanda would then
> need to get
>    the DLEs during the estimate phase or when doing a check of the
> client. This
>    would also be useful in the case where the management of the client
> is separated
>    from the backup management.
>
> I guess some of this issues may be addressed in 2.5
>
> Cheers
>
> Anthony Worrall
>
> #!/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 $full in
>       *K) full=`echo $full | sed -e 's/K//'`;;
>       *M) full=`echo $full | sed -e 's/M//'`; full=$(( $full * 1024 ));;
>       *G) full=`echo $full | sed -e 's/G//'`; full=$(( $full * 1024 *
> 1024));;
>     esac
>     size=$(( $full - $incr ))
>   else
>     size=$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 backup ${DEV}@0
>     else
>       $ZFS backup -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
>
>
>
>
>
>
>
>
>
>


--

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