<p><strong>Region</strong></p> <p>Regions refer to physical data centers that are independent from each other. At present, Ping An Cloud BMS are accessible in six regions: East China1, South China1, Hong Kong, North China1. Data center which is the nearest to you is recommended for shorter access delay and higher access rate.</p> <p><strong>Availability zone</strong></p> <p>An availability zone refers to a physical area with independent power supply and network within a region, and thus it is free from the impacts of failure of other availability zones. Each region is made up of several&nbsp;availability zones. Each availability zone is isolated, but the availability zones in a region are connected through low-latency links, which guarantees both the independence of the availability zones and low-priced, short-delay network connections.</p> <p><strong>VPC</strong></p> <p>VPC (Virtual Private Cloud) refers to a virtual network established in your own logically isolated zone, a totally isolated ad hoc zone for BMS. In VPC, you can configure network characteristics including security groups, VPN, IP address range, band width, etc., which facilitates internal network management and configuration as well as safe and quick network changes. Also, you can define access rules inside and among the security groups so as to strengthen the security of the bare metal servers.</p> <p><strong>Network domain</strong></p> <p>Network domains refer to logically isolated network zones in VPC. At present, BMS supports DMZ and SF network domains. The DMZ network domain can connect with public networks, but the SF network domain cannot. Meanwhile the SF network domain can be accessed to by DMZ, usually being used to deploy APP and DB systems.</p> <p><strong>RAID (Redundant Array of Independent Disks)</strong></p> <p>RAID (Redundant Array of Independent Disks) is a technology that combines independent (physical) disks by different methods to form (logical) disk groups for higher storage performance than a single disk as well as data backup. Different levels of RAID represent different storage performance, data security and storage costs. Ping An Cloud&rsquo;s BMS provides two levels of RAID: RAID5 and RAID10. RAID5 features high read speed but ordinary write speed, suitable for small data blocks and random reading and writing of data, while RAID10 is mainly used for databases with large capacity and needs for speed and error control.</p> <p><strong>Security groups</strong></p> <p>Security groups refer to groups listed in DACLs which are used for resources and instances access rights assignment. A security group consists of two parts: instance lists and security group rules. Users can add BMS instances into instance lists of security groups and assign access rights of BMS instances in the instance lists by security group rules.</p> <p><strong>Product Series</strong></p> <p>At present, Ping An Cloud provides three product series: general-purpose computing, high-performance and big data computing.</p> <ul> <li>General purpose computing: a type of common physical server of BMS, using SAS for data storage, suitable for use cases of general-purpose enterprises applications.</li> <li>High-performance: a type with better performance than general-purpose computing, using SSD and SATA for data storage, with GPU cards, suitable for use cases of high-performance computing and AI.</li> <li>Big data computing: using SAS and SATA for data storage, without GPU cards, suitable for use cases in need of big data computing.</li> </ul>