L1, L2 pair status and supported pair tasks

The pair tasks you can complete on cascaded pairs depend on the L1 and L2 pair status. The tasks are dependent on the following:

  • To perform an L1 pair task, the status of the L2 pair.
  • To perform an L2 pair task, the status of the L1 pair.
  • Supported read/write on L1 and L2 S-VOLs.

The following table lists the L1 pair tasks that you can complete based on the related L2 status.

L2 pair status

L1 pair task

Create pairs

Split pairs

Resynchronize pairs

Suspend pairs

Delete pairs

COPY(PD)/COPY

YES

YES

YES

YES

YES

PAIR

YES

YES

YES

YES

YES

COPY(SP)/COPY

NO

NO

NO

YES

YES

PSUS(SP)/PSUS

NO

NO

NO

YES

YES

PSUS

YES

YES

YES

YES

YES

COPY(RS)/COPY

YES

YES

YES

YES

YES

COPY(RS-R)/RCPY

NO

NO

NO

YES

YES

PSUE

YES

YES

YES

YES

YES

The following table lists the L2 pair tasks that you can perform based on the related L1 status.

L1 pair status

L2 pair task

Create pairs

Split pairs

Resynchronize pairs1

Suspend pairs

Delete pairs

COPY(PD)/COPY

YES

NO

YES

YES

YES

PAIR

YES

NO

YES

YES

YES

COPY(SP)/COPY

YES

NO

YES

YES

YES

PSUS(SP)/PSUS

NO

NO

YES

YES

YES

PSUS

YES

YES2

YES

YES

YES

COPY(RS)/COPY

YES

NO

YES

YES

YES

COPY(RS-R)/RCPY

YES

NO

YES

YES

YES

PSUE

YES

NO

YES

YES

YES

  1. For more information about resynchronizing L2 pairs, see Resynchronizing or restoring ShadowImage pairs.
  2. For more information about the prerequisites for splitting L2 pairs, see Splitting ShadowImage pairs.

The following table lists the node volume read/write L1 and L2 pair status.

L1 Pair Status

L2 pair status

COPY(PD)/COPY

PAIR

COPY(SP)/COPY

PSUS(SP)/PSUS

PSUS

COPY(RS)/COPY

PSUE

COPY(PD)/COPY

Read only

Read only

Read only

Read only

Read only

Read only

Read only

PAIR

COPY(SP)/COPY

PSUS(SP)/PSUS

Read/Write

Read/Write

Read/Write

Read/Write

Read/Write

Read/Write

Read/Write

PSUS

COPY(RS)/COPY

Read only

Read only

Read only

Read only

Read only

Read only

Read only

COPY(RS-R)/RCPY

PSUE

The following table lists the leaf vol read/write per L2 pair status.

L2 pair status

COPY(PD)/COPY

PAIR

COPY(SP)/COPY

PSUS(SP)/PSUS

PSUS

COPY(RS)/COPY

PSUE

Read only

Read only

Read only

Read/Write

Read/Write

Read only

Read only