What is RTO and RPO in SQL Server for Disaster Recovery (BCDR)? Difference Explained

RTO and RPO in SQL Server are the two major factors that organizations must define when they prepare for the SQL Server disaster recovery & business continuity. Here, RTO means Recovery Time Objective & RPO states Recovery Point Objective. In a nutshell, all organizations try to minimize the gap between RTO and RPO for a smooth & secure SQL database running.

This article is going to explain what is RTO and RPO in SQL Server terms & their difference along with other crucial factors that users must pay attention to while creating a disaster recovery plan. Therefore, SLA (service level agreements), a checklist for the same, backup policy, consistency check, alternate solutions, & other significant topics are covered in this blog. We ensure to provide users with complete information on RPO & RTO concerning business continuity and disaster recovery in SQL Server (BCDR).

 

What is RTO ( Recovery Time Objective)?

In terms of SQL Server disaster recovery, RTO is the recovery Time Objective. It states the minimum time required by any organization to fix the server & make it live again after any disaster or incident. Having a very minimal RTO represents that an organization is really capable of fixing server downtime without any hassles.

In other words, we can also say that RTO is the maximum downtime of a server that an organization can bear which disrupts the business continuity to a noticeable extent. An organization that is capable of handling the operations for the longest time until the database is restored is also appreciated.

What is RPO in BCDR for SQL Server?

RPO or Recovery Point Objective is the limit of how much data an organization can afford to lose after a disaster on the database. From the the data which is not backed up before the disaster to the data lost until the server starts running again, is at stake. This is the RTO metric that an organization can tolerate. Organizations that encourage frequent backup often tend to lose less data in such events in comparison to organizations not having frequent backups.

The deciding factor for RPO is how frequently a database administrator takes the backup. Also, a more frequent valid backup can help users minimize the RTO as well. Therefore, frequent backups can increase the overall RTO & RPO standards in any organization.

Service Level Agreements – SLA to Understand RTO & RPO in SQL Database

SLA, also known as the Service Level Agreement is the third lesser-known but crucial parameter among users & vendors. Here, the quality, availability, and responsibilities of the services are taken care of. It is calculated on the basis of RTO and RPO od an organization for SQL Server disaster recovery.

Simply, SLA acts as an umbrella under which, both RTO & RPO are stated in official agreements. It is the security that the vendors provide to the users stating the RTO & RPO standards of the organizations in situations like disaster recovery for further business continuity.

Objectives of RPO & TRO for SQL Server BCDR

Now, that we know the difference between RTO and RPO in SQL Server, we must understand that there is no ready-to-use strategy here. Every business is different in terms of requirements, scope, scale, customers, vulnerabilities, etc.

Therefore, every business should make a different strategy for RTO & RPO as per their specific business requirements. Here, requirements mean the acceptable downtime & data loss that users can bear. This also depends on further factors like users’ need to execute the mission-critical, business-critical, or non-critical SQL server database. Also, budget is another consideration that users have to pay attention to. Below are these considerations discussed in depth

Defining Database Backup Policy in Depth

We all know at this point that frequent backups are equal to short RPO. A short RPO equals minimal data loss. Minimal data loss equals to a short RTO. See, all are connected here in a way. However, building a database backup policy is not as easy as explaining RTO and RPO in SQL Server database for disaster recovery with differences.

Therefore, we are going to list four major key points for users to let them build an effective backup strategy.

• Do not keep the database backup on the same drive where the log files are stored. In case of a hardware issue or bad sector, both the data will wipe out together. Using SAN, Cloud, TAPE, etc platforms are good to store the backups.
• To restore databases larger in size, combine the differential, full, & transaction log backups. It will minimize the downtime & human resources required to get the server back to its original state.
• Full backup & regular transaction log backups are enough for databases that are generally small in size to speed up the entire process.
• No matter if an organization uses ‘VMWare snapshots’, ‘SQL Server Always On Availability Groups’, ‘Failover Clusters’, etc. They must keep regular backups to be on the safe side at the time of an unpredictable disaster.

Also Read: Backup & Restore Database in SQL Server Easily

Define the Database Significance to Set Up the RTO & RPO Values

Users can not set the RTO & RPO values randomly. There should be a solid argument behind that. For example, mission-critical businesses require very short RPO, almost near zero or completely zero. However, for businesses that are not quite mission-critical, the values can be flexible.

For a better understanding, we have mentioned below the range of RTO & RPO in SQL Server disaster recovery which generally ranges between zero to 24 hours.

• Grade A – RTO/RPO less than 15 minutes is for highly mission-critical organizations.
• Grade B – RTO < 2 Hours & RPO of 4 hours is for business critical organizations.
• Grade C – RTO < 4 hours & RPO of 24 hours is for non-critical businesses.

Consistency Check for SQL Server RTO and RPO

Another crucial consideration for users is to keep a regular consistency check. It can be weekly or monthly but it must be regular. It reports in advance about any kind of logical or physical inconsistency errors to let users prepare for or prevent any upcoming disaster.

For DBAs who run frequent pilot project drills for restoration, must check consistency for the restored database as an additional layer of security. Evidently, we have mentioned all other considerations in the below checklist for users to understand RTO and RPO in disaster recovery for SQL Server database.

Checklist for RTO and RPO in SQL Server BCDR

Now, we have a checklist that users must follow to understand what is SQL Server RTO and RPO for disaster recovery & its significance.

• The business escalation matrix, application, and vendor support checklist should be in knowledge of the DBAs to act as fast as they can to minimize the RPO.
• Testing is really important. Therefore, users must test their backups as well as disaster recovery plans after a certain period of time to eliminate any possible loopholes that cause damage to the database.
• Make sure to revise the disaster recovery drills to act wisely in a real SQL disaster situation. Simply, there is no point in conducting drills if users do not pay attention to them at all to understand the difference between RTO and RPO in SQL Server.
• Users must be prepared with a contact owner list for database & applications during any unwanted incident. There is not enough time for users to search for contact owners after a SQL disaster.

What If Our SQL Server Disaster Recovery Plan Fails?

In case, users’ disaster recovery plan for business continuity fails, they must have a plan B. Here, having the SQL Database Recovery Tool is the plan B users are searching for. This advanced utility can help users restore the database even after deletion of the data or getting highly corrupted.

The reason why this utility is the best solution is the recommendations from Microsoft MVPs, SQL experts, etc. Moreover, it offers several advanced features that cut off the need of RPO & RTO as it holds the potential to directly fix the database issues.

Bringing It All Together

Finally, in the end, we all are aware of what is RTO & RPO in SQL Server disaster recovery and business continuity strategy. Moreover, we stated SLA & other key factors to keep in mind for building a robust disaster recovery strategy for SQL Server databases.