ONTAP 9.13

to Japanese version

iSCSI LIF failover for ASA platforms

Beginning with ONTAP 9.11.1 on All-Flash SAN Array (ASA) platforms, the iSCSI LIF failover feature supports automatic and manual migration of iSCSI LIFs in an SFO partner failover (when an iSCSI LIF moves from its home node/port to its HA partner node/port and back again) and in a local failover (when an iSCSI LIF moves from its unhealthy port to a healthy port on its current home node and back again). This feature provides faster I/O resumption for SAN workloads running on ISCSI.

About enabling iSCSI LIF failover

You should familiarize yourself with aspects of when iSCSI LIF failover is automatically enabled and when you must manually enable it, including how newly created iSCSI LIFs and existing iSCSI LIFs are affected.

  • The automatic migration of an iSCSI LIF is a LIF failover and auto-revert, which is triggered in certain events, such as planned or unplanned failover, a physical ethernet link down, or a node dropping out of replicated database (RDB) quorum.

    • After upgrading your ASA HA pair to ONTAP 9.11.1, this feature is automatically enabled on newly created iSCSI LIFs if no iSCSI LIFs exist in the specified storage VM or if all existing iSCSI LIFs in the specified storage VM are already enabled with iSCSI LIF failover.

    • For iSCSI LIFs created prior to upgrading to ONTAP 9.11.1, to use the iSCSI LIF failover feature, you must enable it using the ONTAP CLI. (Enabling the failover feature and auto-revert capability means changing the failover policy to sfo-partner-only and designating the auto-revert value to true.)

      If you do not enable iSCSI LIF failover on the existing iSCSI LIFs, when there is a failover event, the iSCSI LIFs will not failover.

      Additionally, if after upgrading to ONTAP 9.11.1 or later you have existing iSCSI LIFs in a storage VM that have not been enabled with the iSCSI LIF failover feature and you create new iSCSI LIFs in the same storage VM, the new iSCSI LIFs assume the same failover policy (disabled) of the existing iSCSI LIFs in the storage VM.

  • The manual migration of an iSCSI LIF is a LIF migrate and revert, which is initiated by the cluster admin using the ONTAP CLI or ONTAP System Manager.

    You manually migrate and revert an iSCSI LIF under the following circumstances:

    • When scheduled maintenance or replacement is needed.

    • When you have a pre-existing iSCSI LIF, meaning that the iSCSI LIF was created before you upgraded your HA pair to ONTAP 9.11.1 or later, and you have not enabled the iSCSI LIF failover feature on the LIF.

How iSCSI LIF failover works

For LIFs with iSCSI LIF failover enabled (either automatically or manually), the following applies.

  • For LIFs using the data-iscsi service policy, the failover-policy is restricted to sfo-partner-only, local-only, and disabled.

  • iSCSI LIFs can failover only to the HA partner when their failover policy is set to sfo-partner-only.

  • Auto-revert of LIFs happens when the auto-revert is set to true and when the LIF’s home port is healthy and able to host the LIF.

  • On a planned or unplanned node takeover, the iSCSI LIF on the node which is taken-over fails over to the HA partner. The port on which the LIF fails over is determined by VIF Manager.

  • Once the failover is complete, the iSCSI LIF operates normally.

  • When a giveback is initiated, the iSCSI LIF reverts back to its home node and port, if auto-revert is set to true.

  • When an ethernet link goes down on a port hosting one or more iSCSI LIFs, VIF Manager migrates the LIFs from the down port to a different port in the same broadcast domain. The new port could be in the same node or its HA partner. Once the link is restored and if auto-revert is set to true, VIF Manager reverts the iSCSI LIFs back to their home node and home port.

  • When a node drops out of replicated database (RDB) quorum, VIF Manager migrates the iSCSI LIFs from the out of quorum node to its HA partner. Once the node comes back into quorum and if auto-revert is set to true, VIF Manager reverts the iSCSI LIFs back to their home node and home port.

Migrate and revert an iSCSI LIF

You can use ONTAP System Manager or the ONTAP CLI to manually migrate an iSCSI LIF to a different port on the same node or to a different port on the HA partner, and then revert the LIF back to its home node and home port.

Migrate and revert an iSCSI LIF using ONTAP System Manager

You can use ONTAP System Manager to manually migrate and revert one or more iSCSI LIFs (network interfaces) to another port on the same node or to a port on the HA partner.

Before you begin

You must have an ASA platform HA pair and it must be running ONTAP 9.11.1 or later.

Migrate a LIF

Steps
  1. In ONTAP System Manager, click Network > Overview > Network Interfaces

  2. Select the LIF you want to migrate, click Kabob Icon, and then click Migrate.

  3. In the Migrate Interface dialog box, select the destination node and port of the HA partner.

    You have the option of permanently migrating the iSCSI LIF by checking the checkbox. Understand that the iSCSI LIF must be offline before it is permanently migrated. Additionally, once an iSCSI LIF is permanently migrated, it cannot be undone. There is no revert option.
  4. Click Migrate.

Revert a LIF

Steps
  1. In ONTAP System Manager, click Network > Overview > Network Interfaces.

  2. Select the LIF you want to revert, click Kabob Icon and then click Revert Network Interface.

  3. In the Revert Network Interface dialog box, click Revert.

Migrate and revert an iSCSI LIF using the ONTAP CLI

You can use the ONTAP CLI to manually migrate and revert one or more iSCSI LIFs to another port on the same node or to a port on the HA partner.

Before you begin

You must have an ASA platform HA pair and it must be running ONTAP 9.11.1 or later.

If you want to…​

Use this command…​

Migrate an iSCSI LIF to another node/port

See Migrate a LIF for the available commands.

Revert an iSCSI LIF back to its home node/port

See Revert a LIF to its home port for the available commands.

Manage iSCSI LIFs using the ONTAP CLI

You can use the ONTAP CLI to manage iSCSI LIFs, including creating new iSCSI LIFs and enabling the iSCSI LIF failover feature for pre-existing LIFs.

Before you Begin

You must have an ASA platform HA pair and it must be running ONTAP 9.11.1 or later.

About this task

See the ONTAP Command Reference for a full list of network interface commands.

If you want to…​

Use this command…​

Create an iSCSI LIF

network interface create -vserver SVM_name -lif iscsi_lif -service-policy default-data-blocks -data-protocol iscsi -home-node node_name -home-port port_name -address IP_address -netmask netmask_value

If needed, see Create a LIF for more information.

Verify that the LIF was created successfully

network interface show -vserver SVM_name -fields failover-policy,failover-group,auto-revert,is-home

Verify if you can override the auto-revert default on iSCSI LIFs

network interface modify -vserver SVM_name -lif iscsi_lif -auto-revert false

Perform a storage failover on an iSCSI LIF

storage failover takeover -ofnode node_name -option normal

You receive a warning: A takeover will be initiated. Once the partner node reboots, a giveback will be automatically initiated. Do you want to continue? {y/n}:

A y response displays a takeover message from its HA partner.

Enable iSCSI LIF failover feature for pre-existing LIFs

For iSCSI LIFs created before you upgraded your cluster to ONTAP 9.11.1 or later, you can enable the iSCSI LIF failover feature (by modifying the failover policy to sfo-partner-only and by modifying the auto-revert capability to true):

network interface modify -vserver SVM_name -lif iscsi_lif –failover-policy sfo-partner-only -auto-revert true

This command can be run on all the iSCSI LIFs in a Storage VM by specifying “-lif*” and keeping all other parameters the same.

Disable iSCSI LIF failover feature for pre-existing LIFs

For iSCSI LIFs created before you upgraded your cluster to ONTAP 9.11.1 or later, you can disable the iSCSI LIF failover feature and the auto-revert capability:

network interface modify -vserver SVM_name -lif iscsi_lif –failover-policy disabled -auto-revert false

This command can be run on all the iSCSI LIFs in a storage VM by specifying “-lif*” and keeping all other parameters the same.

Top of Page