1) If for your DR/backup you initially write backups to your primary SAN, and then there is a hardware level replication between your primary SAN and DR SAN, therefore the same backup files are on 2 SAN's in differing offices, would this classify as 2 copies of backups. I know for critical systems best practice states have 3 copies, would this class as 2?
2) also - what kinds of issue/risk/incident could take out both your primary SAN and DR SAN, therefore leaving you without live copies of data and backups? our technical team say their DR setup is sufficient, but from our risk angle we want to have some view of risks and probability to see if a 3rd backup is required?
3) And also - given the setup I have described, what options could there be for implementing a 3rd copy of the backup, e.g. tape backup attached to the DR SAN and taken offsite?? The budget is limited so need to determine if a 3rd backup is necessary and what options could be used, and some idea for each option which are the less expensive and which are the more expensive?
4) Is 'primary SAN' the correct terminology to describe your SAN in your main data centre? And is 'DR SAN' the correct terminology to describe the SAN at your DR site?