IBM BPM, V8.0.1, All platforms > Troubleshooting and support > Disaster recovery > Overview of disaster recovery > Disaster recovery procedures
Backing up data
A backup is a copy of the production environment. There are several ways to make a backup. Each method imposes some constraints on the production environment, and each presents some advantages and disadvantages.
- The simple server backup approach uses a packaging
or compression utility to back up the file system.
In a distributed environment, you must back up the data for each server separately.
- The operating system snapshot approach captures the state of a running production system at a specific point in time.
- The operating system snapshot with the shared file system approach captures the state of a running production system at a specific point in time and backs up a distributed production environment.
An example of a shared file system is the Network File System (NFS) on UNIX.
- The operating system snapshot with storage system support approach is the same as the operating system snapshot with the shared file system approach, from a functionality point of view.
A storage system such as Storage Area Network (SAN) can be used to provide a central repository of production environment data.
Each backup method has its own constraints, advantages, and disadvantages, as described in Table 1.
Important: When you choose a method, consider your business requirements.
For example, if a period of downtime is acceptable, the simple server backup is the best choice, because it ensures the consistency of your system.
| Type of backup | Constraints | Advantages | Disadvantages |
|---|---|---|---|
| Simple server | No file system update operations are allowed
during the entire recovery scope.
No work can occur throughout the entire production environment during the backup. | Safe and consistent.
No additional requirements for underlying file system configuration. | Requires significant downtime because no active workload can occur during the backup. |
| Operating system snapshot | The production system can write to only one file system. | Supports hot backup without requiring a stoppage
of activity.
Inexpensive, because it requires only operating system snapshot support. | Backup might not be consistent because of the amount of information being backed up.
Verification process is required to validate the backup. |
| Operating system snapshot with shared file system | Requires one dedicated server to act as the NFS server. | Inexpensive, without requiring a special device.
Supports hot backup without requiring a stoppage of activity. | NFS might introduce performance bottlenecks
because all access goes into the same file system through the network.
NFS is a single point of failure because of centralized management. |
| Operating system snapshot with storage system support | Requires special hardware support. | Supports hot backup without requiring a stoppage
of activity.
Designed for high availability and high performance. Most Storage Area Network (SAN) systems support both periodic snapshots and synchronous replication of data to a remote site. | More expensive.
Requires a more complex configuration. |
To minimize your recovery point objective, determine the ideal backup frequency by considering the business requirements and resources to take and maintain your backups.