Reverse replication
Alternate ways to retrieve data
Under very specific conditions, it could be possible for replica containers to support a type of write operation whose sole function is to restore data from an archival target. For example, data could be replicated back to the remote site where a data management application (DMA), or backup software, is connected to allow this data to be restored directly.
This specific type of case applies only to configurations where data is backed up from a remote location to a local container, and then replicated over a WAN to a replica container that is backed up to tape. The data needs to be restored from the tape backup to the original location; first back to QoreStor replica container, and then back to the original source location of the data on the other side of the WAN link.
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NOTE: If you choose to use this alternate workaround method, you must set up a new data storage unit in your DMA, and import the images before a restore to the original location can occur. |
To leverage this type of deduplication across the WAN, complete the following:
- Make sure that the replication operation has completed (between source and target).
- Delete the current replication relationship, and re-create a replication relationship (reversing the source and target roles).
- Restore data to the original source container (now the target).
- Make sure that the replication operation has completed.
- Delete the replication relationship and re-create a replication relationship (restoring original source and target destinations).
Under this scenario, a fraction of the data to be recovered is sent across the WAN link. This could speed up a remote restore significantly. However, there are some downsides to this type of scenario:
- If step 1 is not followed correctly, any changes not fully replicated are lost.
- During steps 2 and 3, any data that is written to the original QoreStor source container may be lost.
- During step 4, if the data is not fully replicated back before the switch is made, it may be lost.
- Create a new container on the target QoreStor instance.
- Set up replication from this container back to the source QoreStor system container.
- Set up a new disk storage unit in the DMA and make sure that the DMA is aware of any new images.
- Import the old images back into the DMA from the target QoreStor instance (the original source location).
- Use a new disk storage unit in the DMA, and then restore the data back to the original client.
Reverse replication: alternate method
For an alternate method of reverse replication, complete the following steps:
- Create a new container on the target QoreStor instance.
- Set up replication from this container back to the source QoreStor container.
- Set up a new disk storage unit in your Data Management Application (DMA) and make sure that the DMA is aware of any new images.
- Import the old images back into the DMA from the target QoreStor instance (the original source location).
- Use a new disk storage unit in the DMA, and then restore the data back to the original client.
Performance Tiers
In situations where certain workloads have requirements for faster recovery, QoreStor allows you to write these workloads to a performance tier to enable faster read back unaffected by activity in other QoreStor Storage Groups. By utilizing a performance tier, you are able to maximize the value of higher-performing storage by ensuring that only the most critical workloads are written to it.
To create a QoreStor performance tier, you must create a physical volume comprised of high-performing storage (such as SSD) and then create a QoreStor storage group mapped to that volume. Containers created on that storage group will write and read from high-performance storage exclusively and will be isolated from read activity on other volumes.
Cloud Tiering
QoreStor's cloud tiering feature enables on-premesis QoreStor data to be quickly and easily accelerated to the cloud. With a QoreStor Cloud Storage Group and cloud container, local containers can be easily linked to the cloud. Using your existing data management applications (DMAs) and any supported protocol, files can be written to the local QoreStor container are replicated to your cloud storage according to easily defined policies.
During normal operations, many files are actively changing and frequently accessed. Moving these files to cloud storage would have a negative performance impact and increase costs. QoreStor provides a policy engine that allows you to set criteria to be used in identifying which files are most suited for replication to the cloud. Policies are defined at the container level and apply to all files within that container. Using the QoreStor Cloud Policy, you can replicate files based on:
- Idle time - replicate stable files idle for more than the selected number of hours.
- File extensions - replicate files that match or do not match names in a list of extensions.
- File locations - replicated files in a list of directories, or all files except those in a list of directories.
With these policy options, you are able to configure cloud replication to meet one of three use cases:
- Data replication - this creates a direct copy of the backup data stored in QoreStor on the Azure cloud.
- Extended hold - this offloads older and less frequently accessed data to the cloud for long-term archiving.
- Extend and replace - this provides both a direct replica and a long-term archive.
Any data that is transferred out of the on-premesis QoreStor instance by the Cloud Storage Group is encrypted with zero knowledge encryption. The encryption keys are solely owned by you. If the encryption keys are placed in the cloud, a passphrase is used to encrypt those keys and that passphrase is only known to you. For added security, QoreStor obfuscates metadata names such as blockmap and data store objects that are stored in the cloud.