Resync SnapMirror workflow
The Resync SnapMirror workflow
starts a resynchronization operation
to either reestablish a SnapMirror relationship that is broken or to
reestablish a SnapMirror or SnapVault relationship whose updates have failed
due to deletion of a common Snapshot copy from the source volume.
You must be running Clustered Data ONTAP 8.2 or later.
This workflow is typically invoked in the following circumstances:
·
A SnapMirror relationship is broken (that is, the
destination volume is a read/write volume and no longer a data protection
mirror).
For example, a storage
administrator sees a broken SnapMirror relationship and he wants to reestablish the
relationship.
For example,
a storage administrator notes that SnapMirror or SnapVault transfers are
failing because a required common Snapshot copy is missing from the source
volume.
·
To create a SnapMirror or SnapVault
relationships between two volumes that are not in a data protection
relationship but have a common Snapshot copy.
For example,
a storage administrator identifies two volumes that have a common Snapshot copy
but are not in a SnapMirror or SnapVault relationship and he wants to establish
a new relationship between the two volumes.
Additional considerations concerning this workflow include the following:
·
The resync operation
will fail if the destination volume does not have a Snapshot copy in common
with the source volume.
·
The
resync operation might cause data loss on the
destination volume because this operation might remove the exported Snapshot
copy on the destination volume.
1. Click Portal > Data Protection > Resync SnapMirror to display the Executive Workflow dialog box for the Resync SnapMirror workflow.
2. Specify values for the appropriate inputs.
· If you are resynchronizing a broken SnapMirror relationship between the original source volume and original destination volume, or because a required Snapshot copy was deleted on the source volume and SnapMirror transfers are failing, the following user inputs apply:
· Destination Cluster (mandatory)
· Destination Storage Virtual Machine (mandatory)
· Destination Volume (mandatory)
· Maximum Transfer Rate
· Transfer Priority
· Source Snapshot
· If you are resynchronizing because a required Snapshot copy was deleted on the source volume and SnapVault transfers are failing, the following user inputs apply:
· Destination Cluster (mandatory)
· Destination Storage Virtual Machine (mandatory)
· Destination Volume (mandatory)
· Maximum Transfer Rate
· Transfer Priority
· Preserve
· If you are resynchronizing to establish SnapMirror relationship between two volumes that are not in a data protection relationship but do have a common Snapshot copy, the following user inputs apply:
· Destination Cluster (mandatory)
· Destination Storage Virtual Machine (mandatory)
· Destination Volume (mandatory)
· Source Cluster (mandatory)
· Source Storage Virtual Machine (mandatory)
· Source Volume (mandatory)
· Maximum Transfer Rate
· Transfer Priority
· Source Snapshot
3. Click Execute.
User Input |
Description |
Destination Cluster (Mandatory) |
Cluster where the destination volume resides |
Destination Storage Virtual Machine (Mandatory) |
Storage Virtual Machine (SVM) where the destination volume resides |
Destination Volume (Mandatory) |
The destination volume for this resync operation |
Source Cluster (Optional) |
Cluster where the
source volume resides. A value must be specified if the destination volume is not in a SnapMirror or SnapVault relationship. |
Source Storage Virtual
Machine (Optional) |
Name of the SVM where
the source volume resides. A value must be
specified if the destination volume is not in a SnapMirror or SnapVault
relationship. |
Source Volume (Optional) |
Name of the source
volume for the resync operation. A value must be
specified if the destination volume is not in a SnapMirror or SnapVault
relationship. |
Maximum Transfer Rate (Optional) |
Maximum transfer rate,
in kilobytes per second, at which data is transferred. The default (0) is
unlimited which permits the SnapMirror relationship to fully utilize the
available network bandwidth. |
Transfer Priority (Optional) |
Priority at which the resync operation runs. The default value is
the value specified in the SnapMirror policy associated with the
relationship. Valid values are: low,
normal |
Source Snapshot (Optional) |
Snapshot copy on the
source to use for the resynchronization operation. This input affects
the transfer operation in different ways depending on whether the
relationship is SnapMirror or SnapVault and whether the source volume type is
read/write or data protection. See “Snapshot copy transfer behavior” below
for details. |
Preserve (Optional) |
This parameter only applies
to SnapVault relationships. If the value is False,
all Snapshot copies on the destination that are newer than the latest common Snapshot
copy are deleted by the resynchronization operation. If the value is True,
newer Snapshot copies are retained. The default value is False. |
Depending on the
relationship type or source volume type, your input or omission of input to the
Source Snapshot field affects the transfer operation behavior in the following
manner:
SnapVault behavior when source
is read/write |
SnapVault
behavior when source is Data Protection (DP) |
Transfers the selected
Snapshot copy. |
Source Snapshot copy selection is not supported for data protection volumes. |
SnapMirror behavior |
SnapMirror
behavior when relationship is second hop in a SnapMirror to SnapMirror
cascade |
Transfers all Snapshot
copies from the source, up to and including the selected Snapshot copy. |
Source Snapshot copy selection is not supported for data protection volumes. |
When completing the default Resync SnapMirror workflow, WFA executes the following tasks:
1. Search for source volume. WFA calls the No-Op Cluster-Mode command to search for the source volume of the resync operation.
2. Resync SnapMirror. WFA calls the Resync SnapMirror command to start the operation to re-establish a SnapMirror or SnapVault relationship between a source volume and a destination volume.
The resync operation runs in the background on the source and the destination clusters. The Resync SnapMirror command does not wait for the operation to finish.
After the resynchronization operation completes, the SnapMirror or SnapVault relationship can be manually updated or scheduled for updates.
You can customize the default Resync SnapMirror
workflow to clean up the original broken SnapMirror relationship.
Depending on the amount of data to be
resynchronized, the resynchronization operation between the source volume and
the destination volume might require several hours or days to complete;
therefore, the default Resync SnapMirror workflow
does not wait for the resynchronization process to finish.
If you want to customize the Resync SnapMirror
workflow to monitor the operation and wait for it to finish, you can complete
the following step:
1. Add a task
to the workflow that contains a Wait for SnapMirror Resync command
to monitor the resync operation and wait for it to
finish. No specific WFA command is supplied for this purpose, but you can
create one by using the WFA command editing function to clone the current Wait for SnapMirror Initialization command and then customize the clone
to monitor the progress of a SnapMirror resync operation. The
workflow succeeds only if the resynchronization operation finishes
successfully.