Virtual machines make storage more complex

Virtualized server environments pose a small challenge to storage managers, at least to maintain monitoring of data storage and virtual server connections. There are storage management products available on the market that can be applied to this new environment, allowing users to continuously monitor the virtual servers, the applications running on the server, and the storage resources they occupy.

Independent application function

Each datacenter has a typical chimney-style architecture for special applications. Each chimney-style architecture corresponds to a dedicated administrative group and is equipped with a team that is responsible for specific resources in the datacenter, such as networks, servers, storage systems, and virtual tiers. Each management group only focuses on its own area and works with them only when they need to consolidate with other groups. When a new server requires shared storage, the server team and the storage team collaborate to obtain and supply storage resources to the server.

In a traditional physical server environment, storage teams can simply manage the relationship between storage and physical servers: each logical unit Number (LUN) on a storage Area network (SAN) is assigned to only one physical server, and only that server accesses the LUN. Server virtualization has changed all of this. However, storage is perhaps the most critical part of the entire virtualization architecture, so storage deployment and management are directly related to the performance and reliability of the entire architecture. The relationship between server virtualization and storage is so tight that the corresponding management must be in place.

Virtual machines make storage more complex

Virtualization technology is designed to pool physical resources for many virtual machines (VMS). VMware's VMFS Virtualization file system allows multiple physical servers to read and write the same LUN concurrently. This may be based on a unique locking mechanism that ensures that virtual machines on multiple hosts can access the same shared Lun in a field. The advantage of server virtualization is that it provides a highly available and load-balanced virtualization cluster access approach. VMware's vmotion and storage vmotion can switch from one host to another during virtual run-time, or migrate from one storage device to another.

To complicate things, virtual machine migrations on storage devices do not just occur at the virtualization level. Many of today's storage arrays have automated storage tiering capabilities, built into layers of devices, and are pooled and made available to hosts based on different performance characteristics of different devices, such as solid-state and SATA disks. The array migrates data dynamically based on performance requirements. All of this occurs at the storage level, and the virtual host does not realize the migration.

Although the nature of migrating virtual machines is useful, it poses some problems for storage and virtualization administrators. Virtual machines on physical hosts and virtual disks are completely dynamic because of the prior affinity of each virtual machine. The problem arises when you want to detect failures or monitor performance. Because the virtualization administrator is unaware of what is happening on the storage layer, the storage administrator is unaware of the virtual layer and who doesn't know what the system is all about.

(Responsible editor: The good of the Legacy)