To accommodate this situation, VMware lead an alternative element for usage with ALUA devices; however, this is not outlined from the ALUA spec.
ALUA followover just means that when the server finds a beneficial TPG AAS alter so it didn’t end in itself, it doesn’t just be sure to return the change regardless of if they has only accessibility TPGs that will be ANO. Efficiently, which suppress the newest hosts of assaulting getting TPG AAS and you may, rather, they proceed with the TPG AAS of your assortment. Rates six.cuatro and you will 6.5 show ALUA followover interaction that have TPG AAS.
Contour 6.cuatro suggests a health-related storage drawing where in actuality the button fabrics was removed in order to make clear new diagram . Here, TPG ID step 1 ‘s the AO towards Salon, and you may both servers publish the latest We/O compared to that TPG. TPG ID 2 is actually ANO, and that i/O is not delivered to they. This type of TPGs is actually set up with ALUA Specific mode.
Figure 6.5 shows that Host A lost its path to the AO TPG (based on Figure 6.4). As a result, this host takes advantage of the ALUA Explicit mode on the array and sends a SET_TPGS command to the array so that TPG ID 2 is changed to AO and TPG ID 1 is changed to ANO. Host B recognizes that it did not make this change.Read More