Pre-fetching and pre-routing-based routing link establishment method and device applied to SAS Expander

Abstract

The invention provides a route link establishment method and device based on prefetching and prerouting, which are applied to SAS Expander. The method comprises the following steps: an XL receiver receives OAF information in a data stream; when the XL receiver receives the OAF information, the OAF information is forwarded to the ECM of the Expander at the same time; the ECM initiates a pre-routing request to a routing table based on the OAF information to obtain a pre-routing result; after all Dwords in the OAF information are received by the XL receiver, the XL receiver performs CRC (Cyclic Redundancy Check) on the OAF information and sends a check result to an XL state machine; the XL state machine determines whether to generate a link establishment command or not according to a CRC check result of the OAF information; and when a link establishment command is generated, the ECM responds to the link establishment command and initiates a link establishment request to a target disk device based on the pre-routing result. According to the scheme, the ECM routing link establishment process and strategy are optimized, and the routing exchange efficiency of the whole disk array system is improved.

Description

technical field [0001] The invention belongs to the technical field of disk routing, and in particular relates to a routing link building method and device based on pre-fetching and pre-routing applied to SAS Expander. Background technique [0002] The Expander in the disk array system is an expander, which is responsible for routing, switching and service forwarding. like figure 1 As shown, the disk array system implements the access between the host and the large-scale physical disk device through the Expander exchange route. As the number of Expander Phy continues to increase, the performance of the ECM (Expander Connection Manager, Expander Connection Manager), which is the core module of routing and switching in the Expander, will become a key link in the performance of the entire link establishment. How to compress the ECM routing arbitration time and optimize link establishment performance has become an important topic in the design of ECM hardware architecture. ...

AI Technical Summary

Problems solved by technology

Each time XL needs to receive the OAF completely and confirm that the CRC is correct, it can then request the ECM to establish a chain, thus prolonging the chain establishment time

Secondly, since the probability of CRC errors in actual application scenarios is very small, it is often meaningless to wait for CRC confirmation in most cases

If you have to wait for the CRC confirmation information every time before deciding whether to initiate a link building request, it will inevitably reduce the work efficiency of routing link building

Images