Recently, I communicated with a financial institution, and the customer reported that migrating old NAS storage is very slow and takes a long time, with tens of millions of small files. It is very difficult to replace new and old devices. The previous solution is shown in the following figure. The original NAS shared file is mounted to a server, and the target storage file is also mounted to this server. Then, the migration tool is used to continuously migrate data through this intermediate server. First, the data is fully migrated, then, the incremental data is recovered. When the incremental data is relatively small, the business is cut off, the data is leveled up, and the business is mounted to the new storage. With this server transfer migration solution, the speed is up to 800MB/s, the interruption time is not controllable, and the migration time is relatively long, which is really difficult.

The company has developed a new server-free migration solution, as shown in the following figure. The old storage file system is mounted to the new storage, heterogeneous storage, and the new storage is also divided into corresponding file storage directories. The migration relationship between the two is established, mount the newly stored file system to the business system. The original storage service is stopped and transferred to the new storage Mount Directory. The service is restarted and data is migrated through tools in the background. If the data has not been migrated, I/O is forwarded to the old storage through the new storage. With this solution, you can directly migrate data to the storage system. 1. The service interruption time is very short, and you only need to configure the Mount. 2. You do not need to migrate data from servers. The direct connection between storage systems is fast, up to 6 Gb/s, multi-task parallel, and background migration, do not need to wait until the migration is completed before starting the business.

Source: Bi xunshuo