IBM Flex System V7000 Storage Node 4939H49 Manuel D’Utilisation
Codes de produits
4939H49
8068ch09-Copy Servies.fm
Draft Document for Review January 29, 2013 12:52 pm
390
IBM Flex System V7000 Storage Node Introduction and Implementation Guide
Remote Copy consistency groups
A consistency group is a logical entity that groups copy relationships. By grouping the
relationships, you can ensure that these relationships are managed in unison and the data
within the group is in a consistent state. More information about the necessity of consistency
groups can be found in “FlashCopy consistency groups” on page 348.
relationships, you can ensure that these relationships are managed in unison and the data
within the group is in a consistent state. More information about the necessity of consistency
groups can be found in “FlashCopy consistency groups” on page 348.
Remote Copy commands can be issued to a Remote Copy consistency group, and therefore
simultaneously for all Metro Mirror relationships defined within that consistency group, or to a
single Metro Mirror relationship that is not part of a Metro Mirror consistency group.
simultaneously for all Metro Mirror relationships defined within that consistency group, or to a
single Metro Mirror relationship that is not part of a Metro Mirror consistency group.
Figure 9-66 shows the concept of Remote Copy consistency groups. Because the
RC_Relationships 1 and 2 are part of the consistency group, they can be handled as one
entity, while the stand-alone RC_Relationship 3 is handled separately.
RC_Relationships 1 and 2 are part of the consistency group, they can be handled as one
entity, while the stand-alone RC_Relationship 3 is handled separately.
Figure 9-66 Remote Copy consistency group
Remote Copy relationships can only belong to one consistency group, but they do not have to
belong to a consistency group. Relationships that are not part of a consistency group are
called
belong to a consistency group. Relationships that are not part of a consistency group are
called
stand-alone relationships
. A consistency group can contain zero or more relationships.
All relationships in a consistency group must have matching primary and secondary clusters,
which are sometimes referred to as
which are sometimes referred to as
master
and
auxiliary clusters
. All relationships in a
consistency group must also have the same copy direction and state.
Metro Mirror and Global Mirror relationships cannot belong to the same consistency group. A
copy type is automatically assigned to a consistency group when the first relationship is
copy type is automatically assigned to a consistency group when the first relationship is
Important: When using Global Mirror volumes with Change Volumes, make sure that you
remember to select the Change Volume on the auxiliary (target) site. Failure to do so
leaves you exposed during a resynchronization operation.
remember to select the Change Volume on the auxiliary (target) site. Failure to do so
leaves you exposed during a resynchronization operation.
Important: The GUI for Version 6.4.1 automatically creates Change Volumes for you.
However, it is a limitation of this initial release that they are fully provisioned volumes. To
save space, you should create thin-provisioned volumes before and use the existing
volume option to select your change volumes.
However, it is a limitation of this initial release that they are fully provisioned volumes. To
save space, you should create thin-provisioned volumes before and use the existing
volume option to select your change volumes.