In my next few posts, I will discuss three topics about DPM 2007 SP1.
- A good backup choice? This will discuss how to “sell” this product to the IT decision takers and talks about the ROI of the product
- How it works. This will discuss more how the product works in and what snapshotting is on a high level, not to technical.
- How to start a DPM project. This will discuss (based on the IPD from Microsoft) what the best way is to prepare for a DPM project.
To understand the next few topics, I will give here a few definitions that are used in the product. (taken from the technet site)
RPO: RPO means Recovery Point Objective. This means the following: What is the amount of data that is tolerated to lose in case of a disaster. In many cases, the business will say no loss :-). But since that is almost impossible (unless you have sophisticated systems such as SAN replication etc…).
Retention Range: Basically, how long must data kept for availability. Most known example is the GFS principle which stands for Grandfather, Father, Son.
RTO: Recovery Time Objective. How fast do you need to be online again. Most of the time, IT decision takers need to find a balance between the RTO and the RPO which is a very difficult exercise.
End-User Recovery: Will the end-users be able to do recovery there selves without intervention of IT?
BCP / DRP: Business Continuity Plan / Disaster Recovery Plan. The first is about figuring out if the business can continue to run after a disaster and the second is more about recovering what is lost.
Data Source: The data that DPM considers as a unit for protection. DPM allocates separate storage for each data source.
Differential Backup: This term is not used with DPM. It refers to a backup in which all of the files that are new, or have changed since the last backup, are backed ip.
Express Full Backup: A type of backup that only transfers blocks that changed since the previous express full backup. This creates a recovery point.
Incremental backup (sync): A type of backup that uses the application’s native form of incremental data protection.
For example, for a server running SQL Server, it’s a log file backup; and for a server running Exchange Server, it’s a VSS incremental backup. Each incremental backup creates a new recovery point. With incremental backups, only the data that has changed since the most recent full or incremental backup are backed up, which means that the size of the incremental backup is usually much smaller than a full backup.
Replica: A full copy of a protected data source that reflects the result of the most recent DPM operation for that data source.
Replica Volume: A volume that holds the current copy of the protected data for a data source.
Synchronization: The process by which DPM transfers changes to protected data from the protected computer to the DPM server, and applies the changes to the replica of the protected volume.
Volume Shadow Copy Services (VSS): Provides the backup infrastructure for the Windows XP, Windows Vista®, Windows Server 2003, and Windows Server 2008 operating systems, as well as a mechanism for creating consistent point-in-time copies of data known as shadow copies.
Protection Group: One or more data sources that are grouped together, to be protected in the same way, by the same DPM server.
Consistency Check: The process by which DPM checks for and corrects inconsistencies between a protected data source and its replica. A consistency check is performed only when normal mechanisms for recording changes to protected data, and for applying those changes to replicas, have been interrupted.
Recovery Point: The point in time view of a previous version of a data source that is available for recovery from media managed by DPM.
That’s it for now, next post: A good backup choice?
Cheers,
Mike
