Reverse replication
The concept of reverse replication is not a supported operation on QoreStor. This is because replica containers are always in a R-O (read-only) mode on QoreStor, thus making write operations a non-supported operation.
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.
Alternatively, you could still support this type of effort by completing the following:
- 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 Tier
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 Tier
QoreStor's cloud tier feature enables QoreStor data to be quickly and easily accelerated to the cloud tier. Using your existing data management applications (DMAs) and any supported protocol, files can be written to a QoreStor container and replicated to your cloud tier according to easily defined policies.
QoreStor provides a policy engine that allows you to set idle time and on-premises retention 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.
- Regular expressions - include or exclude files based on their match to configured regular expressions.
- File locations - replicated files in a list of directories, or all files except those in a list of directories.
In addition, there is an On-Prem Retention Age policy that allows you to specify how long a copy of a file is kept after it has been replicated to the cloud tier. Once a file has been replicated, the file on the QoreStor server becomes a stub, meaning it exists in the namespace but the data exists only in the cloud tier. Once a file has been stubbed and moved to the cloud tier, that file can no longer be edited.
With these policy options, you are able to configure cloud tier replication to meet one of three use cases:
- Data replication - this creates a direct copy of the backup data stored in QoreStor on the cloud tier.
- Extended hold - this offloads older and less frequently accessed data to the cloud tier for long-term archiving.
- Replicate and extend - this provides both a direct replica and a long-term archive.
Any data that is transferred from the QoreStor instance by the cloud tier is encrypted with zero knowledge encryption. The encryption keys are solely owned by you. If the encryption keys are placed in the cloud tier, 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 tier.
