SCSI Management
| SCSI enclosures provide electrical power, thermal cooling, and other support for the operation of SCSI target devices. Two in-band techniques for management of SCSI enclosures warrant mention. The first is the SCSI Accessed Fault-Tolerant Enclosures (SAF-TE) specification. The most recent SAF-TE specification was produced by the nStor Corporation and the Intel Corporation in 1997. SAF-TE provides a method of monitoring fault-tolerant SCSI enclosures using the following six SCSI commands:
All six of these commands are defined in the ANSI T10 SCSI Primary Commands (SPC) specification series. SAF-TE is a proprietary specification that is published in an open manner. SAF-TE is not a de jure standard. That said, the goal of SAF-TE is to provide a nonproprietary method for heterogeneous SCSI controllers to monitor heterogeneous storage enclosures. SAF-TE is implemented as a SCSI processor inside the enclosure. The SAF-TE SCSI processor supports target functionality. The SCSI controller (initiator) periodically polls the SAF-TE target using the aforementioned commands to detect changes in enclosure status such as temperature and voltage levels. The SAF-TE target can also assert indicators (for example, lights and audible alarms) to indicate the status of enclosure components such as fans, power supplies, and hot-swap bays. The second in-band technique is called SCSI Enclosure Services (SES). SES is defined in the ANSI T10 SES specification series. SES provides a method of monitoring and managing the components of a SCSI enclosure. SES is conceptually similar to SAF-TE, and SES has the same goal as SAF-TE. However, SES is a standard, and ANSI development of SES is ongoing. Like SAF-TE, SES is implemented as a SCSI target. SES operation is similar to SAF-TE, but SCSI controllers (initiators) use only two commands to access SES:
Both of these commands are defined in the ANSI T10 SPC specification series. |
EAN: 2147483647
Pages: 196