Although this example may seem somewhat exaggerated, however, the laws are also fully applicable in information technology. Therefore, one should not neglect the creation of an “extra” incremental backup before updating the system. If a company cannot afford to “waste time” on “preventative” backup, then you should consider using a failover cluster, automatic hardware snapshots of storage systems, or other ways to ensure the system’s constant availability without compromising the reliability of its data.
Perform a full backup immediately after a significant system update.
- The full backup is created on Fridays; incremental backups are made on the remaining days.
- On Wednesday, the database server was upgraded to a new version, which was accompanied by updating some common system files related to the operating system.
- On Thursday night, as usual, an incremental backup was obtained.
- On Thursday morning, there was a critical failure that demanded a system recovery.
After examining the nature of the failure, the administrator realizes that only the system files are damaged and to restore the system’s functioning it would be enough to restore only a lot of system files using the latest full backup. However, if you only do this, then the updated version of the database server will stop working, as it requires newer versions of the system files (for example, the latest version of the .NET Framework) that were installed with it. This leads to the need to continue the recovery process by looking at the necessary incremental backups that contain changes to the system state. This ultimately leads to an increase in the complexity of the recovery process and an increase in the RTO time, up to a violation of the SLA. You can visit usedynamics.com for the perfect options there.
The general recommendation can be formulated as follows: if the cumulative volume of incremental backups exceeds the volume of the full backup, it is rational to make an unscheduled full backup.
Perform a full backup immediately after system recovery
This is a variation of the previous paragraph. Restoring a system after a crash is a time-consuming process, often requiring considerable time (due to the need to use incremental backups, various patches that were not included in the backups, etc.). In some cases, users immediately begin to work in the system, as soon as its basic functionality is restored and thereby begin to change its state. Besides, you cannot exclude re-failure after a short period after the first. Therefore, it is reasonable immediately after the restoration to fix in a full back up a new actual state of the system.
“Do not chase after two hares” or “Modernization is evil.”
It is not necessary to combine the process of restoring the system after failures and the process of its modernization. Despite the fact that this may seem obvious, the lack of time for technological procedures during the continuous production operation of the system and the unwillingness to make (even necessary) changes to “what is already working normally”. It may cause the desire to use the moment of forced downtime at the time of failure in order to perform upgrades, so to speak “for one thing”.