Here are some basic steps. We happen to have our MDS in VMWARE so this makes it easy. We can keep the OLD MDS up and running and then after we export the MDS we can put the NIC in a Dummy VLAN. This allows us to build a new MDS with the same IP and do the import and verify. If anything goes wrong, we never touched the primary MDS it is still running. We just shutdown the new MDS and then put the old MDS NIC back in the the proper VLAN. You need to test this process. It worked for R77.20 to R80 fine. Also I did this in our LAB from R80EA3 to R80GA. However the R80EA3 was never in production so I did not fully test everything after migration.
1) Export from Primary
Expert
unset TMOUT
mkdir /var/log/workarea
cd /
ln -s /var/log/workarea .
cd /workarea
mkdir export
mdsstop
Put R80 ISO in CDROM (VMWARE)
cd /mnt
mkdir cdrom
mount /dev/cdrom /mnt/cdrom
cd /mnt/cdrom/linux/p1_install
./mds_setup
Choose export (without logs)
Proceed Yes
target /workarea/export
Newer than R80 - No
2) Setup new MDS
Run the first time wizard.
reboot
mkdir /var/log/workarea
cd /
ln -s /var/log/workarea .
cd /workarea
mkdir export
cd export
4)FTP the export file to the import dir
5) start the import
mds_import.sh /workarea/import/exported_mds.<date>.tgz
