Disaster Recovery - Failover with an accessible primary volume

If a catastrophic event occurs on the primary site and the primary storage is still accessible, customers can take the following steps to quickly access their data on the secondary site.

Before you start the failover, make sure that all host-authorization is in place.

Authorized hosts and volumes must be in the same data center. For example, you can't have a replica volume in London and the host in Amsterdam. Both must be in London or both must be in Amsterdam.

Authorizing the host

You can create the authorization in the UI, from the CLI, with the API, or with Terraform.

Starting a failover from a volume to its replica

If a failure event is imminent, you can start a Controlled Failover or an Immediate failover your destination, or target, volume.

A Controlled Failover is the best choice when you want to test the failover function. It's also the best choice, when it’s more important to continue operations at the replica location with the most recent data. In a Controlled Failover, a new snapshot is taken and copied over to the replica location. After the data is successfully copied over, the volume is made available for mounting.

When you choose an Immediate Failover, the last successfully replicated snapshot is activated, and the volume is made available for mounting. The target volume becomes active in less time compared to a Controlled Failover. However, any data that was written to the source volume since the previous replication cycle is lost.

When a failover is started, the replication relationship is flipped. Your original target volume becomes your active source volume, and your former source volume becomes your inactive replication target.

Failovers are started under Storage, File Storage for Classic in the IBM Cloud® console.

Before you proceed with these steps, disconnect the volume. Failure to do so results in corruption and data loss.

Failing over to replica in the console

Click your active volume (“source”).
Click Actions .
Select Failover. Select Controlled Failover or Immediate Failover.
Mark the checkbox to acknowledge pertinent information and click Yes to proceed. A window is displayed to confirm that the failover is in progress. Click Close to return to the File shares list.
In the list, locate your shares. If you have multiple pages, you might need to go to the next page to see the shares.
The status of your source and replica shares is displayed as 'Failback in progress'. Additionally, an icon appears next to your volume on the File Storage for Classic that indicates that an active transaction is occurring. Hovering over the icon produces a window that shows the transaction details. The icon disappears when the transaction is complete.

During the failover process, configuration-related actions are read only. You can't edit any snapshot schedule or change snapshot space. The event is logged in replication history. When your target volume is live, you get another message. Your original source volume's Status becomes Inactive.
Refresh the page in your browser. When the transaction is complete, your replica volume has Active status, and your original source volume becomes Inactive.
Mount and attach your storage volume to the host. For more information, see connecting your storage.

Failing over to replica from the CLI

Before you begin, decide on the CLI client that you want to use.

You can either install the IBM Cloud CLI and install the SL plug-in with ibmcloud plugin install sl. For more information, see Extending IBM Cloud CLI with plug-ins.
Or, you can install the SLCLI.

Initiating a failover from the IBMCLOUD CLI

You can use the ibmcloud sl file replica-failover command to fail over operations from the source file share to the replica file share. The following example initiates a failover from the source share 560156918 to the replica share 560382016.

$ ibmcloud sl file replica-failover 560156918 560382016
OK
Failover of volume 560156918 to replica 560382016 is now in progress.

For more information about all of the parameters that are available for this command, see ibmcloud sl file replica-failover.

Initiating a failover from the SLCLI

To fail over a file volume to a specific replicant volume, use the following command.

$ slcli file replica-failover --help
  Usage: slcli file replica-failover [OPTIONS] VOLUME_ID

  Options:
   --replicant-id TEXT  ID of the replicant volume
   --immediate          Failover to replicant immediately.
   -h, --help           Show this message and exit.

During the failover process, configuration-related actions are read only. You can't edit any snapshot schedule or change snapshot space. The event is logged in replication history. When your target volume is live, you get another message. Your original source volume's Status becomes Inactive.

Starting a failback from a volume to its replica

When your original source volume is repaired, you can start a controlled Failback to your original source volume. In a controlled failback:

The acting source volume is taken offline.
A snapshot is taken.
The replication cycle is completed.
The just-taken data snapshot is activated.
The source volume becomes active for mounting.

When a Failback is started, the replication relationship is flipped again. Your original source volume is restored as your active source volume, and your target volume becomes the inactive target volume again.

Failing back in the console

Failbacks are started under Storage, File Storage for Classic in the IBM Cloud® console.

Click your active volume ("target").
On the Share Details page, click Actions .
Select Failback.
Mark the checkbox to acknowledge pertinent information and click Yes to proceed.
A window is displayed to confirm that the failover is in progress. Click Close to return to the File shares list.
In the list, locate your shares. If you have multiple pages, you might need to go to the next page to see the shares.
The status of your source and replica shares is displayed as 'Failback in progress'. Additionally, an icon appears next to your volume on the File Storage for Classic that indicates that an active transaction is occurring. Hovering over the icon produces a window that shows the transaction details. The icon disappears when the transaction is complete.

During the failback process, configuration-related actions are read only. You can't edit any snapshot schedule or change snapshot space. The event is logged in replication history.
Refresh the page in your browser. When the transaction is complete, the original source share is shown as Active, and the replica share has an Inactive status.
Mount and attach your storage volume to the host. For more information, see connecting your new storage.

Failing back from the CLI

Initiating a failback from the IBMCLOUDCLI

You can use the ibmcloud sl file replica-failback command to fail back operations from the replica file share to the original source file share. The following example initiates a failback to the original source share 560156918.

$ ibmcloud sl file replica-failback 560156918
OK
Failback of volume 560156918 is now in progress.

For more information about all of the parameters that are available for this command, see ibmcloud sl file replica-failback.

Initiating a failback from the SL CLI

To fail back a file volume from a specific replicant volume.

$ slcli file replica-failback --help
   Usage: slcli file replica-failback [OPTIONS] VOLUME_ID

   Options:
    --replicant-id TEXT  ID of the replicant volume
    -h, --help           Show this message and exit.

During the failback process, configuration-related actions are read only. You can't edit any snapshot schedule or change snapshot space. The event is logged in replication history.