ALUA settings are from the LUNs in combination with TPGs

An illustration from a keen EMC VNX otherwise CLARiiON CX Array

This output shows the Stores Assortment Form of field set to VMW_SATP_ALUA_CX, which is the same as the VMW_SATP_ALUA plug-in with additional code to handle certain commands specific to CLARiiON CX ALUA arrays.

The output also shows the Shop Selection Sorts of Product Config line, wrapped for readability, which includes a number of parts:The first set of curly brackets, , includes initiator subscription–particular setting. It is certain so you're able to EMC VNX as well as the CLARiiON group of arrays. Inside put, one or two choices are noted:

navireg=to the-This means that NaviAgent Registration option is enabled on this host. It registers the initiator with the VNX or CX array if it is not already registered. Note that you need to check the initiator record on the array to make sure that Failover Mode is set to 4, which enables ALUA for this initiator. (You can find more details on this in Chapter 7.)

ipfilter=on-This option filters the host’s IP address so that it is not visible to the storage array. (You’ll learn more about this in Chapter 7.)

The newest ALUA AAS management form choices are closed when you look at the one minute number of curly mounts, within this that’s several other nested collection of curly supports towards TPG’s AAS setting. These represent the ALUA AAS government form alternatives:

Explicit_allow=towards-This means that the host is configured to allow the SATP to exercise its explicit ALUA capability if the need arises (for example, in the event of a failed controller).

action_OnRetryErrors=out of-This option is set to off by default. This means that when and I/O on that path returns an error indicating the I/O can be retried, the path remains in an on state even after the I/O is retried indefinitely. When this option is set to on, the path eventually, after a certain timeout, is marked dead if the I/O retries still result in an error. (You’ll learn more about this in Chapter 7.)

TPG_id-This field shows the target port group ID. If the LUN is accessible via more than one target port group (typically two groups), both IDs are listed here. This example has TPG_id step 1 and 2. Each TPG is listed within its own pair of curly brackets.

TPG_state-This field shows the AAS of the TPG. Notice that TPG_id 1 is in AO AAS, whereas TPG_id dos is in ANO AAS. Based on this configuration, I/O is sent to TPG_id step 1.

A lot more Examples away from an enthusiastic EMC VNX/CLARiiON CX Range

The first device in this example shows TPG_id step 1 being in AO AAS, and on the second device, TPG_id dos is also in the same state (AO AAS). This means that the devices are spread evenly over the array’s SPs. For example, TPG 1 on SPA services I/O to LUN 2, whereas TPG 2 on SPB services I/O to LUN 0. You should also notice from the Operating Pathways field that for LUN 2, the target portion of the pathname is T2, via vmhba2 and vmhba3, whereas it is T3 for LUN 0. (I explain in Chapter 2, “Fibre Channel Storage Connectivity,” Chapter 3, “FCoE Storage Connectivity,” and Chapter 7, “Multipathing and Failover,” how to identify which target belongs to which SP.)

Both devices are claimed by VMW_PSP_RR (round-robin). https://datingmentor.org/sugar-daddies-uk/aberdeen/ This means that the I/Os rotate on SPA ports via vmhba2 and vmhba3 for LUN 2, whereas for LUN 0, the I/Os rotate on SPB ports via the same HBAs. This design balances the load on the storage array SPs as well as the host’s initiators. (I explain this in Chapter 7.)