Protecting CloudPools SmartLink Files
Fri, 12 Jan 2024 17:20:14 -0000
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Dell PowerScale CloudPools SmartLink files are the sole means to access file data stored in the cloud, so ensure that you protect them from accidental deletion.
Note: SmartLink files cannot be backed up using a copy command, such as secure copy (scp).
This blog focuses on backing up SmartLink files using OneFS SyncIQ and NDMP (Network Data Management Protocol).
When the CloudPools version differs between the source cluster and the target PowerScale cluster, the CloudPools cross-version compatibility is handled.
NDMP and SyncIQ provide two types of copy or backup:
- Shallow copy (SC)/backup: Replicates or backs up SmartLink files to the target PowerScale cluster or tape as SmartLink files without file data.
- Deep copy (DC)/backup: Replicates or backs up SmartLink files to the target PowerScale cluster or tape as regular files or unarchived files. The backup or replication will be slower than for a shallow copy backup. Disk space will be consumed on the target cluster for replicating data.
The following table shows the CloudPools and OneFS mapping information. CloudPools 2.0 is released along with OneFS 8.2.0. CloudPools 1.0 is running in OneFS 8.0.x or 8.1.x.
Table 1. CloudPools and OneFS mapping information
OneFS version | CloudPools version |
OneFS 8.0.x/OneFS 8.1.x | CloudPools 1.0 |
OneFS 8.2.0 or higher | CloudPools 2.0 |
The following table shows the NDMP and SyncIQ supported use cases when different versions of CloudPools are running on the source and target clusters. As noted in the following table, if CloudPools 2.0 is running on the source PowerScale cluster and CloudPools 1.0 is running on the target PowerScale cluster, shallow copies are not allowed.
Table 2. NDMP and SyncIQ supported use cases with CloudPools
Source | Target | SC NDMP | DC NDMP | SC SyncIQ replication | DC SyncIQ replication |
CloudPools 1.0 | CloudPools 2.0 | Supported | Supported | Supported | Supported |
CloudPools 2.0 | CloudPools 1.0 | Not Supported | Supported | Not Supported | Supported |
SyncIQ
SyncIQ is CloudPools-aware but consider the guidance in snapshot efficiency, especially where snapshot retention periods on the target cluster will be long.
SyncIQ policies support two types of data replication for CloudPools:
- Shallow copy: This option is used to replicate files as SmartLink files without file data from the source PowerScale cluster to the target PowerScale cluster.
- Deep copy: This option is used to replicate files as regular files or unarchived files from the source PowerScale cluster to the target PowerScale cluster.
SyncIQ, SmartPools, and CloudPools licenses are required on both the source and target PowerScale cluster. It is highly recommended to set up a scheduled SyncIQ backup of the SmartLink files.
When SyncIQ replicates SmartLink files, it also replicates the local cache state and unsynchronized cache data from the source PowerScale cluster to the target PowerScale cluster. The following figure shows the SyncIQ replication when replicating directories including SmartLink files and unarchived normal files. Both unidirectional and bi-directional replication are supported.
Note: OneFS manages cloud access at the cluster level and does not support managing cloud access at the directory level. When failing over a SyncIQ directory containing SmartLink files to a target cluster, you need to remove cloud access on the source cluster and add cloud access on the target cluster. If there are multiple CloudPools storage accounts, removing/adding cloud access will impact all CloudPools storage accounts on the source/target cluster.
Figure 1. SyncIQ replication
Note: If encryption is enabled in a file pool policy for CloudPools, SyncIQ also replicates all the relevant encryption keys to the secondary PowerScale cluster along with the SmartLink files.
NDMP
NDMP is also CloudPools-aware and supports three backup and restore methods for CloudPools:
- DeepCopy: This option is used to back up files as regular files or unarchived files. Files can only be restored as regular files.
- ShallowCopy: This option is used to back up files as SmartLink files without file data. Files can only be restored as SmartLink files.
- ComboCopy: This option is used to back up files as SmartLink files with file data. Files can be restored as regular files or SmartLink files.
It is possible to update the file data and send the updated data to the cloud storage. Multiple version SmartLink files can be backed up to tape using NDMP, and multiple versions of CDOs (Cloud Data Objects) are protected in the cloud under the data retention setting. You can restore a specific version of a SmartLink file from tape to a PowerScale cluster and continue to access (read or update) the file as before.
Note: If encryption is enabled in the file pool policy for CloudPools, NDMP also backs up all the relevant encryption keys to tapes along with the SmartLink files.
Thank you for taking the time to read this blog, and congratulations on knowing the solutions for protecting SmartLink files using OneFS SyncIQ and NDMP.
Author: Jason He, Principal Engineering Technologist