Scenario:

– a standalone ESXi with a 2.8TB datastore in Australia has to be cloned to Brasil

– problems: no physical access is possible and access via idrac is unreliable

 

Why clone a complete datastore at all ?

– after an “incident” one VM  has disappeared and is hiding among 20 other working VMs – thats why we need to move the raw volume and cant move single VMs

 

Current plan:

– setup an iSCSI target in the vicinity of the standalone host

– connect to the iSCSi-target and create a second datastore

– dd the complete original datastore by reading the device /dev/disks/naa.number:3 split in 10gb chunks piped into gzip to the second datastore

– upload 267 gz files to a webserver available in the internet

– download the gz-files to the location in Brasil, check md5sums and reassemble the datastore

 

Script to split the dd-dumps in Australia looks like this:

 

#!/bin/sh

DUMP=”/dev/disks/naa.6842b2b06bce1b001fa1a45e08787efd:3″

TARGET=”/vmfs/volumes/iscsi/parts”

 

RANGEMIN=0

RANGEMAX=267

x=$RANGEMIN

 

while [ $x -le $RANGEMAX ]

do

  echo “dd part number $x”

  echo “dd part number $x” >>  $TARGET/clone-log.txt 

echo “dd part number $x” >>  $TARGET/error.txt

 

dd if=$DUMP  bs=1M count=10240 skip=$(( $x * 10240 )) | gzip -c > $TARGET/dump-$x.gz

echo “$?” >>  $TARGET/error.txt

 

if [ ! -e $TARGET/dump-$x.gz  ];

then

    echo “$TARGET/dump-$x.gz does not exist”  >>  $TARGET/error-log.txt;

fi

 

echo “md5sum part number $x”

md5sum $TARGET/dump-$x.gz > $TARGET/dump-$x.md5

 

if [ ! -e $TARGET/dump-$x.md5  ];

then

    echo “$TARGET/dump-$x.md5 does not exist”  >>  $TARGET/error-log.txt;

  fi

 

  x=$(( $x + 1 ))

done

 

Any suggestions on how to impove speed, improve error-messages or for additional dd-parameters are welcome.

In case one of the 10gb slices fails because of I/O errors I plan to address those slices separately via dd-rescue from a Linux-system.