Hello, everyone!
What is storage virtualization?
Storage virtualization enables a storage device to be converted to a logical data store. A VM is stored as a set of files in a directory on a data store. A datastore is a logical container that is similar to a file system. It hides the features of each storage device and forms a unified model to provide disks for VMs. The storage virtualization technology helps the system manage virtual infrastructure storage resources with improved resource utilization and flexibility, and improves application uptime.
Storage virtualization solution
FusionCompute provides host-based storage virtualization, hiding the complexity of storage device types and bypassing performance bottlenecks. Storage virtualization ls Implemented by virtualizing physical storage resources into logical resources. Resources of different storage devices are integrated and provided in a unified manner Based on the storage Virtualization technology FusionCompute provides multiple storage services to improve Storage utilization, reliability, maintainability, and user experience.
FusionCompute hides peculiarities of different storage devices, including IP SAN, Fiber Channel (FC) SAN, and network-attached storage (NAS) devices, and local disks and offers file-level service operations based on file Systems. FusionCompute provides comprehensive storage-related functions, such as thin provisioning, incremental Snapshots, Storage cold and live migration, linked clones, and VM disk capacity expansion.
In addition, FusionCompute supports data store expansion,， which allows one data store to manage multiple physical LUNs, thereby effectively improving the data store expansibility.
Multipathing
Multipathing is a storage access mechanism that provides more than one physical path to connect a network storage device to one or more host NICs, enabling load sharing for data flows and thereby enhancing reliability for storage access.
Typically, multipathing is supported by iSCSI and FC storage devices, such as IP SAN devices, FC SAN devices, and OceanStor 18000 series storage devices.
The storage multipathing mode is universal multipathing.
Technical principles of multipathing
Sample Storage Multipathing Networking
As shown in figure, the storage device, Huawei OceanStor S5500T for example, has two controllers, A and B. Each controller controls four storage NICs. The four NICs are assigned to four VLANs, which constitute the storage plane.
On a host, two NICs are used to connect to the storage plane. Each host NIC communicates with storage NICs on two VLANs. In this case, two storage ports are required for each host NIC.
Integration mode of multipathing software and OSs
The following figure shows the layer where the Ultrapath driver resides on the Windows, Linux, or Solaris platform.
UltraPath function - Failover
UltraPath automatically delivers I/Os to the path again after the path recovers from a fault.
Paths can be restored in either of the following ways:
For a system that supports hot swap(such as Windows), the link between the host and the storage device is disconnected. As a result, the SCSI device is deleted. After the link recovers, the SCSI device is created again. In this scenario, UltraPath can detect the path recovery immediately.
For systems that do not support hot swap(such as AIX and Linux of earlier versions), UltraPath detects path recovery through periodic tests.
How do I prepare storage resources?
1. Add and associate with storage resources.
2. Scan storage devices.
3. Add data stores.
Storage virtualization enables a storage device to be converted to a logical data store. A VM is stored as a set of files in a directory on a data store. A data store is a logical repository that is similar to a file system. It can combine storage devices of different types and provide a unified model to store VM files. The storage virtualization technology helps the system manage virtual infrastructure storage resources with high resource utilization and flexibility.
The following storage units can be encapsulated as data stores:
1. Logical unit numbers (LUNs) on storage area network (SAN) storage, including Internet Small Computer Systems Interface (iSCSI) and fibre channel (FC) SAN storage
2. File systems on network attached storage (NAS) devices
3. FusionStorage Block storage resource pools
4. Local hard disks
Data stores support the following file systems:
1. Virtual Image Management System (VIMS)
The VIMS is a high-performance file system that is designed for storing VM files. The VIMS data can be stored on a local or shared storage device that is based on Small Computer System Interface (SCSI), such as Fibre Channel (FC), fiber channel over Ethernet (FCoE), and iSCSI devices.
2. Network File System (NFS)
The NFS runs on NAS devices. FusionSphere supports the NFS V3 protocol. It can connect to the custom NFS disks on the NFS server and have these disks attached to meet storage requirements.
3. Ext4
FusionSphere supports virtualization of local disks on servers.
1. Relationship between FusionSphere storage virtualization and VIS
Relationship between FusionSphere storage virtualization and VIS: FusionSphere supports storage virtualization, heterogeneous storage, and also VIS. FusionSphere can be independently used as a virtualization solution. In this solution, a cluster must use the same storage device and storage multipathing software. Typically, different vendors use different storage multipathing software. Therefore, when multiple vendors and a small number of storage devices are required, dividing these storage devices into one cluster is not supported. As a result, the requirement cannot be met. VIS is a Huawei storage virtualization product, supports hybrid configuration of IP SAN and FC SAN. VIS is mainly used to manage storage devices from multiple vendors, shield storage differences, and provide unified LUNs. If you need to divide storage devices from multiple vendors into one cluster, use the VIS product.
If the VIS product is added, the system performance will degrade and the cost will increase.
2. Differences between FusionCompute storage virtualization and non-virtualization
FusionCompute uniformly transforms storage units of storage resources into data stores that can provide hard disk resources for VMs. After the storage resources are encapsulated into data stores and associated with the host, several virtual disks can be created for VMs.
Differences between FusionCompute storage virtualization and non-virtualization:
Virtualized data store: The speed of creating a common disk is slow, but some advanced features are supported. If a thin disk is created, more advanced features can be supported, thereby improving storage resource utilization and system security and reliability.
Non-virtualized data store: The speed of creating a disk is fast, the performance of non-virtualized data stores is prior to that of virtualized data stores. However, non-virtualized data stores do not support advanced features.
That's all, thanks!
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