By Li Wuxian from Huawei

Enterprise data is stored in professional storage. For large enterprises comprising many data centers and massive volumes of data, storage is often a pain point. Storage devices need to both provide instant access and take up less floor space, all at a lower price than other alternatives. Storage device replacement is required when devices are out of warranty, end of life, or encounter insufficient performance and capacity.

Replacing storage devices involves business integration and data migration. Data migration does not mean simply moving data from one place to another. Instead it involves data security, compatibility, migration efficiency, outage time, as well as considerations of its impact on business. Currently, there are three main types of data migration: at the application layer, at the host layer, and at the storage layer. Because of the many different aspects surrounding storage and data migration, it is no wonder that it is the focus of many industry giants. From a customer standpoint, enterprises need to effectively judge how data migration will impact their business and services. Further, they need to find ways to both enable online data takeover and migration, and ensure a quick migration speed, as well as choose a solution that delivers an easy-to-use interface for future business expansion and integration. During this process, if any financial challenges arise, consulting with a firm rescue skilled or insolvency practitioner can offer the guidance needed to navigate complexities and maintain financial stability while focusing on growth and development.

Analysis of Mainstream Data Migration Solutions

Data migration at the application layer: A major migration method based on database and virtual machines (VMs) functions at the application layer, this solution is used in cross-platform and cross-media migration scenarios and scenarios with short downtime. It features simple access to the target storage and little impact on the source network topology. In some scenarios, migration and replacement tolerate short service interruption.

Because this method of storage requires host resources during data migration, it can create huge pressure on service systems. It is often associated with low migration speeds, sometimes even less than 200 MB/s. In addition, has application-layer migration solutions have restrictions on application configuration. For example, Oracle ASM Rebalance supports only Oracle ASM to manage disks, and VMware Storage vMotion does not support online migration in some scenarios (VM shared disks and RDM disks, etc.).

Data migration at the host layer: implemented by the volume management software. Common Veritas Volume Manager (VxVM) of a third party and Logical Volume Manager (LVM) of AIX, HP-UX, and Linux are used to migrate data online. Host-layer migration solutions ensure that services are not interrupted during migration, satisfying storage space consolidation and cross-media migration demands. However, the solutions may provide slow migration speeds of less than 100 MB/s, as well as large consumption of host CPU and memory resources. In addition, manual inputting of command lines is required during the migration, which is prone to errors.

Data migration at the storage layer: Utilizes the built-in functions of storage devices to migrate data at the storage layer. These functions are as follows:

LUN copy and remote replication: used for migration between homogeneous storage, where the migration speed of LUN copy can reach up to 500 MB/s.

Remote replication: used for long-distance migration, where its online migration speed is about 100 MB/s on average.

Heterogeneous virtualization: uses storage virtualization functions to take over data from heterogeneous devices and then migrate the data to the source end. Its migration speed is up to 500 MB/s and third-party storage devices are supported.

Data migration at the storage layer features fast migration speeds and does not impact host system performance. Likewise, there is no vendor lock-in, allowing users to migrate to and from third-party storage devices. However, LUN copy is offline, and the switchover of remote replication service takes a long time. Heterogeneous virtualization is insufficient, and the takeover requires the device to suspend.

Storage-layer migration solutions need to provide non-disruptive data migration processes, and support online takeover migration.

Based on these demands, Huawei launched OceanStor V5 Hybrid Flash Storage, OceanStor F V5, and OceanStor Dorado All Flash Storage series. These are business-unaware migration solutions with zero downtime perfectly designed to optimize heterogeneous virtualization, implementing online takeover and migration of data at the storage layer.

Huawei’s Heterogeneous Virtualization Data Migration Solution

OceanStor V5 Hybrid Flash Storage, OceanStor F V5, and OceanStor Dorado All Flash Storage series adopt SmartVirtualization and SmartMigration in heterogeneous virtualization migration scenarios. These functions migrate data in the source array to the target array at the storage layer. Users can use SmartVirtualization to take over the source array (third-party storage) online, and then migrate the data online by using SmartMigration. After the migration is complete, users can remove the source storage from the live network.

Implementation Principles of Huawei’s Heterogeneous Virtualization Migration Solutions

Customers can move data from third-party storage to Huawei’s storage External LUNs on third-party storage devices to store actual data. These Huawei devices are commonly known as eDevLUNs. An eDevLUN consists of a Meta Volume and a Data Volume.

The Meta Volume is used to manage the data organization of eDevLUNs. The storage space of Meta Volumes is provided by Huawei’s storage devices, and occupies little space.

A Data Volume is a logical abstract object of external LUN data. An external LUN provides all data storage space. eDevLUNs created on Huawei’s storage systems have one-to-one mapping relationships with external LUNs. Application servers manage data on external LUNs through data reads and writes on eDevLUNs.

In a heterogeneous virtualization solution, LUNs mapped to source arrays are taken over during the initial migration phase, and LUNs of third-party storage are initialized into eDevLUNs that can be managed by the target arrays under the condition that no data is lost. LUNs are migrated using value-added features of heterogeneous virtualization, which enables data to be rapidly migrated between the source and target arrays. Heterogeneous takeover can be performed online, and the services are non-disruptive during data replication.

Huawei’s Online Migration Technologies in Heterogeneous Virtualization Scenarios

Compared with takeovers in traditional heterogeneous virtualization scenarios, Huawei’s takeover can encapsulate the source LUNs into eDevLUNs without interrupting host services. Huawei’s storage maps the eDevLUNs to the host so that the hosts’ multi-pathing software can automatically aggregate the physical paths of the source LUNs and eDevLUNs. The software runs host multi-pathing commands to delete the corresponding physical links of the source LUNs and switch all I/Os to the link to implement online takeover with zero downtime.

Process of Online Takeover and Migration

1. Connect the source arrays to the target arrays, and map the LUNs to be migrated to Huawei’s disk arrays.
2. The Huawei’s disk arrays encapsulate the LUNs mapped to the source arrays into eDevLUNs that are then mapped to the source host.
3. Use multi-pathing software on the host system to aggregate physical links between the source LUNs and eDevLUNs and delete the physical links of the source LUNs to complete online takeover.
4. After the online takeover, use SmartMigration to migrate data from the source LUNs to Huawei’s disk arrays to implement online data migration.

Advantages of Huawei’s Online Migration in Heterogeneous Virtualization Scenarios

• Mainstream operating systems can be used to migrate data between SAN storage arrays from different vendors.
• During migration, data is replicated on storage arrays, which does not occupy CPU or memory resources of the host, imposing zero impact on business.
• Services are not interrupted during array takeover and data migration
• Data migration speed can reach up to 500 MB/s.
• Data can be migrated conveniently and quickly without installing any extra software or agent in the existing environment.
• Migration Director is a professional migration tool that supports automatic operation on an efficient graphical user interface.

The post Huawei’s Business Integration Solution: A Revolutionary Optimal Data Migration Method appeared first on Huawei Enterprise Blog.

Source: Huawei Enterprise Blog
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