The powerful nature of multipathing and failover requires the freedom of handling and managing an ALUA TPGa€™s AAS

The powerful nature of multipathing and failover requires the freedom of handling and managing an ALUA TPGa€™s AAS

The reverse holds true for TPG with That is actually, it is AO for LUN 2 and ANO for LUN 1.

On some active/passive ALUA-capable arrays, you may read interface communities with a€?Standbya€? AAS instead of a€?ANOa€? from the non-owner SP.

Asymmetric Accessibility County

Harbors in an ALUA TPG can be in the same AAS always with respect to a given LUN. The TPG’s AAS are reported to the initiators in reaction on REPORT TPGS command. The TPG descriptor was reported in byte 1 of these reaction.

Transitioning-The TPG AAS is in the procedure for switching from just one state to a different. Assuming the SP of an AO TPG is being rebooted or perhaps is used traditional, or if the SAN (storage area network) admin by hand transfers LUN possession (on EMC CLARiiON, this is exactly known as trespass), the AAS with the TPG from the different SP variations to AO. While this techniques try continuous, the TPG AAS was transitioning.

Although the TPG is within this state, receiving needs through the initiators go back ACTIVE or a CHECK PROBLEM with feeling crucial NOT EAGER and ASC (additional feeling signal) LOGICAL UNIT never OBTAINABLE or ASYMMETRIC ACCESS STATE CHANGE.

Standby-This condition is similar to a passive SP in a non-ALUA setting and on some ALUA-capable arrays. They returns a CHECK STATE with awareness essential NOT READY.

After TPG is during this AAS, they supports a subset of instructions this takes when it is in AO AAS:

Unavailable-This AAS is generally viewed once the TPG’s accessibility the LUN is fixed because of hardware mistakes or any other SCSI equipment limits. A TPG inside condition cannot transition to AO or ANO till the mistake subsides.

ESXi 6 directs the I/O to TPGs which are in AO AAS, in case they are certainly not offered, I/O is sent to TPGs which are in ANO AAS. Leia mais