What Is DSS?

Dedicated Distributed Storage Service (DSS) provides you with dedicated storage pools which are physically isolated from other pools to ensure high security. With data redundancy and cache acceleration technologies, DSS delivers highly reliable, durable, low-latency, and stable storage resources. By flexibly interconnecting with various compute services, such as Dedicated Computing Cluster (DCC), Elastic Cloud Server (ECS) and Bare Metal Server (BMS), DSS is suitable for different scenarios, including high performance computing (HPC), online analytical processing (OLAP), and mixed loads.

Figure 1 DSS architecture

Advantages

A variety of specifications
- High I/O: Suitable for scenarios that require high performance, high read/write speed, and real-time data storage.
- Ultra-high I/O: Excellent for read/write-intensive scenarios that require extremely high performance and read/write speed, and low latency.
Elastic scalability
- On-demand capacity improves resource utilization.
- Linear performance increase can be achieved with capacity expansion.
Security and reliability
- Distributed storage with three data replicas ensures 99.9999999% durability.
- System disks and data disks support data encryption with zero application awareness.
Backup and restoration
- Backups can be created for a DSS disk, and the backup data can be used to restore the disk data, maximizing data security and correctness and ensuring service security.

Differences Between DSS and EVS

**Table 1** Differences between DSS and EVS
Service	Overall Introduction	Storage Category	Typical Application Scenarios	Performance
DSS	DSS provides exclusive physical storage resources for users. The storage pools are physically isolated, and data durability reaches 99.9999999%. Multiple types of compute services, including DCC, ECS and BMS, can be interconnected with DSS at the same time. DSS has abundant features to guarantee data security and reliability.	Dedicated storage pools, which means that storage pools are physically isolated and resources are exclusively used.	Interconnection with compute services, such as ECS and BMS, in a dedicated cloud. Interconnection with compute services, such as ECS and BMS, in a non-dedicated cloud. Mixed load. DSS supports hybrid deployment of HPC, database, email, OA, and web applications. High-performance computing OLAP applications	High I/O storage pool: The initial specification is 13.6 TB, which can be expanded to a maximum of 435.2 TB in 13.6 TB increments. The maximum IOPS is 1,500 IOPS/TB. Ultra-high I/O storage pool: The initial specification is 7.225 TB, which can be expanded to a maximum of 289 TB in 7.225 TB increments. The maximum IOPS is 8,000 IOPS/TB.
EVS	Elastic Volume Service (EVS) provides scalable block storage that features high reliability, high performance, and rich specifications for servers.	Shared storage pools	Enterprise office applications Development and testing Enterprise applications, including SAP, Microsoft Exchange, and Microsoft SharePoint Distributed file systems Various databases, including MongoDB, Oracle, SQL Server, MySQL, and PostgreSQL	EVS disks start at 10 GB and can be expanded as required in 1 GB increments to a maximum of 32 TB.