Solid-State Disks: Pushing the Envelope in Blade Server Design
Focus Areas for Carrier Grade Linux
Carrier Grade is a telecommunications and networking industry term for systems that must be available 99.999 percent of the time, known as "5 nines." This level of availability implies that "5 nines" compliant products do not require more than 5 minutes of downtime per year. The "Carrier Grade" label imposes even stricter requirements for minimal downtime and high availability than the more general information technology term "24x7," which means continuous operation, 24 hours a day and 7 days a week.
The OSDL's CGL specification defines a standard set of requirements that satisfy the needs of the telecommunications and networking industries, and that provide a common base for developing interoperable software. In conjunction with related telecommunications and networking hardware standards, the CGL specification provides a firm foundation for the development of standard, high-performance, highly-available, scalable, and easily-serviced platforms.
The CGL specification groups requirements into the categories shown in the following table, listed alphabetically.
| Requirement | Definition |
| Availability | Capabilities associated with high availability, such as reducing single points of failure, resource failover, multipath I/O, fast restart, the ability to force and remotely manage system reboots and upgrades, and so on. |
| Clustering | Requirements for using multiple, connected, carrier grade systems as a single computing resource in order to provide higher levels of service, increased scalability, improved performance, and increased uptime. |
| Performance | Features required to satisfy responsiveness and general performance goals. These include soft real-time support, constant-time scheduling, process priority inheritance, processor affinity, specific mechanisms for handling flexible amounts of transient data, and so on. |
| Platform | Hardware-related standards and supported interfaces that must be provided by a CGL Linux distribution in order to work with standard telecommunications and network equipment provider standards such as ATCA. | Scalability | Requirements necessary to support carrier-class server systems where adding hardware resources and associated software configuration metadata produces appropriate increases in performance and capacity. |
| Security | Facilities to protect and ensure the consistency of carrier grade systems and the data that they contain. |
| Serviceability | Capabilities associated with remote administration and management of systems running a CGL distribution. | Standards | The core set of services and capabilities that must be available in a CGL Linux distribution. These include references to POSIX, IEEE, ISO, and Linux standards such as the Linux Standard Base (LSB) runtime compatibility specification, which in turn reference other Linux standards such as the Filesystem Hierarchy Standard (FHS). |
| Tools | Requirements for tools that support application and system development, debugging, and performance analysis, including tools that enable analysis and debugging for deployed systems and applications. |
The requirements that comprise each of the sections of the CGL 2.0 specification are prioritized into one of three different levels. These are:
- Requirement is mandatory and must be satisfied in a CGL system in order for it to be compliant with the specification.
- Requirement is desirable but not mandatory.
- Requirement is identified as relevant to some CGL systems but is not currently viewed as critical.
As discussed in more detail later in this white paper, CGL 2.0 Linux distributions must demonstrate that they have met all priority 1 requirements or provide a technical explanation for any non-compliance. These CGL registrations must be published openly and can therefore be readily examined by any potential user of that distribution.
Previous Page | Next Page
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8
If you found this page useful, bookmark and share it on:
If you are familiar with RSS feeds, you can also sign up for our free blog feed. Our RSS feed is updated in real-time while our newsletter is updated daily.