The reverse is true for TPG with that was, it’s AO for LUN dos and you may ANO getting LUN step one.
Towards the specific active/couch potato ALUA-in a position to arrays, you are able to see port teams which have “Standby” AAS as opposed to “ANO” on non-owner SP.
Asymmetric Availability County
Ports in an ALUA TPG can be in the same AAS at all times with respect to a given LUN. The TPG’s AAS are reported to the initiators in response to the Declaration TPGS command. The TPG descriptor is reported in byte 1 of that response.
Transitioning-The TPG AAS is within the means of modifying from one condition to another. Such as for instance, in the event the SP of a keen AO TPG is being rebooted otherwise was drawn off-line, or if the fresh new SAN (space for storing network) admin by hand transmits LUN ownership (to your EMC CLARiiON, this will be called trespass), the fresh new AAS of your TPG toward approach SP transform to help you AO. Although this procedure is lingering, this new TPG AAS was transitioning.
While the TPG is in this state, receiving requests from the initiators return Busy or a Check Reputation with sense key Maybe not Able and ASC (additional sense code) Analytical Product Maybe not Available or ASYMMETRIC Accessibility Condition Change.
Standby-This state is similar to a passive SP in a non-ALUA configuration and on certain ALUA-capable arrays. It returns a Check Reputation with sense key Maybe not Able.
When the TPG is within it AAS, it supporting a great subset regarding requests this allows if this is during AO AAS:
Unavailable-That it AAS can often be viewed if the TPG’s usage of this new LUN is restricted right down to knowledge mistakes or other SCSI device limitations. A beneficial TPG inside county struggles to transition to AO or ANO up until the error subsides.
ESXi six delivers brand new I/O to help you TPGs which might be when you look at the AO AAS, however, if they are certainly not readily available, I/O is distributed to TPGs which can be in the ANO AAS. If your shop range receives sustained I/O to your TPGs which might be inside ANO AAS, the newest range transitions the fresh new TPG’s county so you’re able to AO AAS. Which tends to make you to definitely transform utilizes this new ALUA government mode from the brand new shops array (comprehend the 2nd area).
ALUA Management Modes
This is done thru a collection of orders and you can answers so you’re able to and you may in the storage arrays. These instructions are as follows:
Inquiry-According to SPC-3, section 6.4.2, in response to this command, an array returns certain pages of the VPD (vital product data) or EVPD (extended vital product data). The inquiry data returned in response to this command includes the TPGS field. If the returned value in that field is nonzero, that device (LUN) supports ALUA. (See Table 6.3, later in this chapter, for the correlation between the value of the TPGS field and AAS management modes.)
Place Address Vent Organizations (Put TPGs)-This command requests that the storage array set the AAS of all ports in specified TPGs. For example, a TPG’s AAS can transition from ANO to AO via the Put TPGs command.
Dining table six.step one ALUA AAS administration settings
Not Supported-The response to the Report TPGs and Set TPGs commands is invalid. This means that the storage array does not support ALUA or, in the case of EMC CLARiiON, the initiator records are not configured in a mode that supports ALUA.
Implicit-The array responds to Report TPGs but not Set TPGs commands. In this case, setting the TPG’s AAS is done only by the storage array.
Explicit-The array responds to both Declaration TPGs and Place TPGs commands. In this case, setting the TPG’s AAS can be done afroromance ekЕџi only by the initiator.