As you know, ZDLRA is one appliance dedicated to provides you zero data loss in several (planned and unplanned) outages. All the backups are stored inside of the delta store to be processed, and they are deconstructed, meaning that the rman backup set does not exist (as is the formal backup set file).
But sometimes we need to copy/extract some backups outside of ZDLRA and copy it to the filesystem. Maybe because some regulations/compliances need to store for long-term/archival purposes. But some caveats are important to be explained.
The Platinum architecture is the last defined at MAA references and is the highest level of protection that you can achieve for MAA. It goes beyond the Gold protection (that I explained in my previous post) and you can have application continuity even version upgrade for your database.
The Gold architecture for MAA is used to emphasis the application continuity. All the possible outages (planned or no) are protected by Oracle features. Here we are one step further and start to design using multi-site architecture. Data Guard, RAC, Oracle Clusterware, everything is there. But even with these, ZDLRA is still needed to allow complete protection.
With the MAA references, we have the blueprints and highlights how to protect them since the standalone/single instance until the multiple site database. But for Gold we are beyond RPO and RTO, they are important but application continuity and data continuity join to complete the whole picture.
The MAA defined Silver architecture for database environments that use (or need) high availability to survive for outages. The idea is having more than one single instance running, and to do that, it relies on Oracle Clusterware and Engineered Systems to mitigate the single point of failure. But is not just a database that gains with this, the Silver architecture is the first step to have application continuity. And again, ZDLRA is there since the beginning.
As you can see above, the Silver by MAA blueprints improves compared with Bronze architecture that I spoke at the last post. But the basic points are there: RPO and RTO. They continue to base rule here. And the goals are the same: Data Availability, Data Protection, Performance (no impact), Cost (lower cost), and Risk (reduce). More technical details here at the MAA Overview doc.
Oracle Maximum Availability Architecture (MAA) means more than just Data Guard or Golden Gate to survive outages, is related to data protection, data availability, and application continuity. MAA defines four reference architectures that can be used to guide during the deploy/design of your environment, and ZDLRA is there for all architectures.
With the MAA references, we have the blueprints and highlights how to protect them since the standalone/single instance until the multiple site database. The MAA goal is to survive an outage but also sustain: Data Availability, Data Protection, Performance (no impact), Cost (lower cost), and Risk (reduce).
Survive to disk failures it is crucial to avoid data corruption, but sometimes, even with redundancy at ASM, multiple failures can happen. Check in this post how to use the undocumented feature “mount restricted force for recovery” to resurrect diskgroup and lose less data when multiple failures occur.
Diskgroup redundancy is a key factor for ASM resilience, where you can survive to disk failures and still continue to run databases. I will not extend about ASM disk redundancy here, but usually, you can configure your diskgroup without redundancy (EXTERNAL), double redundancy (NORMAL), triple redundancy (HIGH), and even fourth redundancy (EXTEND for stretch clusters).
If you want to understand more about redundancy you have a lot of articles at MOS and on the internet that provide useful information. One good is this. The idea is simple, spread multiple copies in different disks. And can even be better if you group disks in the same failgroups, so, your data will have multiple copies in separate places.
As an example, this a key for Exadata, where every storage cell is one independent failgroup and you can survive to one entire cell failure (or double full, depending on the redundancy of your diskgroup) without data loss. The same idea can be applied at a “normal” environment, where you can create failgroup to disks attached to controller A, and another attached to controller B (so the failure of one storage controller does not affect all failgroups). At ASM, if you do not create failgroup, each disk is a different one in diskgroups that have redundancy enabled.
When configuring a database with Real-Time Redo at ZDLRA it is important to check the deletion policy for archivelog. This is even more important when the database is protected with dataguard. I already wrote about Real-time Redo in this previous post, and when using with dataguard in another post.
But sometimes (during maintenance as an example) you can face the error RMAN-08137: warning: archived log not deleted, needed for standby or upstream capture process if the deletion policy of archivelog is not aligned with your needs.
In my previous post, I showed how the clone to tape occurs for ZDLRA. But as explained, the clones occur through the scheduler and follow some rules. For full backup, as an example, it clones the last available.
But sometimes, it is needed to call the clone for some specific backup, maybe to do long-term storage to follow some regimentation/law. And if we leverage this for the clone, jobs can maybe take to long, or clone more that you need.
As you saw in my last post, the configuration to enable clone to tape for ZDLRA it is not complicated, but you need to take care of some details to avoid errors. Besides that, ZDLRA relies on OSB to do that (when configured with native tape support) and this has some details that you need to be aware of.
In this post, I will show how the clone to tape works for ZDLRA. And how you can check some details about OSB.
With ZDLRA you can clone your backups to tape using two ways. The first is using third-party software and the second is using Oracle Secure Backup (OSB). This integration from ZDLRA and OSB is the native way to do that.
Cloning backups to tape will help to offload backups from ZDLRA (reducing the space usage if you need to sustain long recovery windows), and add another layer of protection (since you can put tapes in a third site).
Here I will show how easy is to configure the OSB backup and how to integrate it into your backup policy.