Migration / Backup

[Manuele]

I have two questions (which probably have been discussed before :)))

What do u suggest to migrate all the mailboxes from:
server A running cyrus 1.6.24 to
server B running cyrus 2.1.12
there aren't many mailboxes, but most of them are over 100M
and at least 2 of them are over 1G

What is the preferred backup solution for 2.1.12?
My main concern is about HD failures among other possible problems

TIA