The prestartfcconsistgrp command prepares a consistency group (a group of FlashCopy® mappings) so that the consistency group can be started. This command flushes the cache of any data that is destined for the source VDisk and forces the cache into the write-through mode until the consistency group is started.
Syntax
>>- svctask -- -- prestartfcconsistgrp -- --+------------+-- ---> '- -restore -' >--+- fc_consist_group_id ---+--------------------------------->< '- fc_consist_group_name -'
Parameters
- -restore
- (Optional) Specifies the restore flag. This forces the consistency group to be prepared even if the target VDisk of one of the mappings in the consistency group is being used as a source VDisk of another active mapping. An active mapping is in the copying, suspended, or stopping state.
- fc_consist_group_id | fc_consist_group_name
- (Required) Specifies the name or ID of the consistency group that you want to prepare.
Description
This command prepares a consistency group (a group of FlashCopy mappings) to subsequently start. The preparation step ensures that any data that resides in the cache for the source VDisk is first flushed to disk. This step ensures that the FlashCopy target VDisk is identical to what has been acknowledged to the host operating system as having been written successfully to the source VDisk.
You can use the restore parameter to force the consistency group to be prepared even if the target VDisk of one or more mappings in the consistency group is being used as a source VDisk of another active mapping. In this case the mapping restores as shown in the svcinfo lsfcmap view. If the restore parameter is specified when preparing a consistency group where none of the target VDisks are the source VDisk of another active mapping, then the parameter is ignored.
You must issue the svctask prestartfcconsistgrp command to prepare the FlashCopy consistency group before the copy process can be started. When you have assigned several mappings to a FlashCopy consistency group, you must issue a single prepare command for the whole group to prepare all of the mappings at once.
The consistency group must be in the idle_or_copied or stopped state before it can be prepared. When you enter the prestartfcconsistgrp command, the group enters the preparing state. After the preparation is complete, the consistency group status changes to prepared. At this point, you can start the group.
If FlashCopy mappings are assigned to a consistency group, the preparing and the subsequent starting of the mappings in the group must be performed on the consistency group rather than on an individual FlashCopy mapping that is assigned to the group. Only stand-alone mappings, which are mappings that are not assigned to a consistency group, can be prepared and started on their own. A FlashCopy mapping must be prepared before it can be started.
An invocation example
svctask prestartfcconsistgrp 1
The resulting output
No feedback