Bare metal backup, or image backup, is a powerful backup and recovery solution. It copies the entire hard drive block by block without working around complex application logic, rather than treating data as bits and bytes stored in hard drive sectors. Subsequent backups can detect and only copy changed blocks. Some bare metal backup solutions go one step further, providing filters that allow the removal of certain folders and files from the hard drive image. Most organizations provision bare metal backup for servers to protect files, emails, database, virtual machine instances and the hard drive.
Relying solely on Bare Metal Restore to backup files, Exchange, and application aware data can cause problems. It is critical that organizations consider using a backup solution that carries application logic and only backup data changed for that application. In discussions with many Managed Service Providers (MSP), it was noted that they typically will rely on StorageCraft ShadowProtect for files, Exchange, and application data and although it has filters, the MSP will usually end up repeatedly backing up the same data causing exponential and unwarranted data growth and incurring more storage capacity requirements.
Over time, this results in two major problem areas:
1. Storage used is growing too fast and capacity constraints are invoked.
2. Applications like SQL, Exchange does not overtly record completed backup status.
The first issue is major. The nature of bare metal backup is to copy blocks that have changed since last full image backup, which include both data and system changes. However application data is only a data change and usually at smaller size, the application itself is not needed to backup. As bare metal backup is dealing with large amount of data, usually in hundreds of GBs, the proper solution is to backup to local NAS device first, then replicate to remote cloud storage for secondary copy. This scenario typically leads to the purchase or licensing of more storage capacity. In addition, the bandwidth is constrained and will quickly reach maximum as there is more replication of larger amounts of image backups.
Applications like SQL and Exchange internally log when a backup was completed, this is important to note when critical data is backed up regularly. However, bare metal backup may not trigger these applications to write such a log. This ultimately could present an issue for audit.
In summary, bare metal backup is a powerful backup solution to protect the hard drive with OS and data, in case of a disaster, it can bring back the hard drive as it is in a matter of minutes. However, to backup application aware data, a proper backup agent shall be selected for this task.