Data Migration is the process of selecting and moving data from one location to another – this may involve moving data across different storage vendors, and across different formats.
Data migrations are often done in the context of retiring a system and moving to a new system, or in the context of a cloud migration, or in the context of a modernization or upgrade strategy.
Data migrations can be laborious, error prone, manual, and time consuming. Migrating data may involve finding and moving billions of files, which can succumb to storage and network slowdowns or outages. Also, different file systems do not often preserve metadata in exactly the same way, so migrating data without loss of fidelity and integrity can be a challenge.
Network Attached Storage (NAS) migration is the process of migrating from one NAS storage environment to another. This may involve migrations within a vendor’s ecosystem such as NetApp to NetApp or across vendors such as NetApp to Isilon or EMC to NetApp or EMC to Pure FlashBlade. A high-fidelity NAS migration solution should preserve not only the file itself but all of its associated metadata and access controls.
Network Attached Storage (NAS) to Cloud migration is the process of moving data from an on-premises data center to a cloud. It requires data to be moved from a file format (NFS or SMB) to an Object/Cloud format such as S3. A high-fidelity NAS to Cloud migration solution preserves all the file metadata including access control and privileges in the cloud. This enables data to be used either as objects or as files in the cloud.
Storage migration is a general-purpose term that applies to moving data across storage arrays.
Data migrations typically involve four phases:
- Planning – Deciding what data should be migrated. Planning may often involve analyzing various sources to find the right data sets. For example, several customers today are interested in upgrading some data to Flash – finding hot, active data to migrate to Flash can be a useful planning exercise.
- Initial Migration – Do a first migration of all the data. This should involve migrating the files, the directories and the shares.
- Iterative Migrations – Look for any changes that may have occurred during the initial migration and copy those over.
- Final Cutoff – A final cutoff involves deleting data at the original storage and managing the mounts, etc., so data can be accessed from the new location going forward.
Resilient data migration refers to an approach that automatically adjusts for failures and slowdowns and retries as needed. It also checks the integrity of the data at the destination to ensure full fidelity.