Shield redundant LUNs
In a multi-path networking storage network, an application server that does not have multipathing software installed will pass each path.A LUN is discovered, so the same LUN is considered to be two or more different LUNs.Remaining LUN. A redundant LUN is generated by directly reporting a LUN to the application server.
Take the dual-link direct connection to the storage system networking as an example, as shown on the left side of the following figure. As shown in the figure, the storage system is mapped to only one LUN of the application server. Since the application server has two paths to the storage system and the multi-path software is not installed, the application server discovers two LUNs of LUN0 and LUN1 at the same time. LUN. These two LUNs are actually the same LUN on the storage system. Due to the identification error of the application server, when the application server performs the write operation, different applications repeatedly write different data to the same location of the same LUN, and finally the data written on the LUN is destroyed. In this case, the application server needs to identify which one is actually available.
UltraPath can query the configuration of the storage system, so it can identify which LUNs can actually be used by the application server. As shown in the figure on the right, after the UltraPath is installed on the application server, the UltraPath shields the redundant LUNs at the operating system driver level and provides only one available LUN, called a virtual LUN. In this environment, the application server only needs to submit data read and write operations to the UltraPath. The UltraPath can shield the application server from redundant LUNs and correctly write data to the LUN without destroying other data.
