Sharing volumes with Thin Image

ShadowImage User Guide

Version
9.8.5
Audience
anonymous
Part Number
MK-98RD9021-15

You can share SI volumes with HTI volumes. You can assign shared pairs to CTGs, but not to the same CTG. For the node or leaf volume of a Thin Image pair, see the S-VOL description in the following table.

The following table describes how you can share HTI volumes.

HTI volume

SI volume

P-VOL

S-VOL

P-VOL (RCPY status)

NO

NO

P-VOL (all statuses except RCPY)1

YES

YES2

S-VOL

NO

NO

HTI pool volume

NO

NO

Notes:

  1. SI cannot use a Thin Image P-VOL in RCPY status.

    For more information about sharing volumes, see the following tables.

  2. You must create the SI pair before you create the HTI pair.

SI pair tasks that you can perform are limited according to the Thin Image pair status. The following topics show the supported SI tasks.

Pair tasks with Thin Image primary volume shared with ShadowImage primary volume

The following table lists the pair tasks that you can perform when you share the SI P-VOL with the Thin Image P-VOL.

SI task

(CCI command)

Thin Image pair status

COPY

PAIR, PFUL

PSUS, PFUS

SMPL(PD)

RCPY

PSUE

Create a pair (paircreate)

YES

YES

YES

YES

NO

YES

Create and split a pair (paircreate -split)

YES

YES

YES

YES

NO

YES

Split a pair (pairsplit)

YES

YES

YES

YES

NO

YES

Resynchronize a pair (pairresync)

YES

YES

YES

YES

NO

YES

Reverse Copy a pair (pairresync -restore)

YES

YES*

YES

YES

NO

YES

Quick Restore a pair (pairresync -restore)

NO

NO

NO

NO

NO

NO

Suspend a pair task (pairsplit -E)

YES

YES

YES

YES

YES

YES

Delete a pair (pairsplit -S)

YES

YES

YES

YES

YES

YES

Notes:

*The snapshot data must be consistent with P-VOL data and ready to use in the SI task.

After issuing the pairsplit command for a Thin Image pair for which a consistency group is configured, verify that the status of all pairs in the Thin Image consistency group is PSUS or unpaired, and then execute the SI task. If you do not, the Thin Image snapshot data and P-VOL data when the storage system accepted the pairsplit command will not be consistent. For details about Thin Image pair status and operations, see the Hitachi Thin Image User Guide.

For more information about ensuring the snapshot data is consistent with P-VOL data, see Ensuring snapshot data is consistent with P-VOL data.

Pair tasks with Thin Image primary volume shared with ShadowImage secondary volume

The following table lists the pair tasks that are supported when you share the SI S-VOL with the Thin Image P-VOL.

SI task

(CCI command)

Thin Image pair status

COPY

PAIR, PFUL

PSUS, PFUS

SMPL(PD)

RCPY

PSUE

Create a pair (paircreate)

NO

NO

NO

NO

NO

NO

Create and split a pair (paircreate -split)

NO

NO

NO

NO

NO

NO

Split a pair (pairsplit)

YES

YES1

YES

YES

NO

YES

Resynchronize a pair (pairresync)

YES

YES1

YES

YES

NO

YES

Reverse Copy a pair (pairresync -restore)

YES

YES1

YES

YES

NO

YES

Quick Restore a pair2 (pairresync -restore)

NO

NO

NO

NO

NO

NO

Suspend a pair task (pairsplit -E)

YES

YES

YES

YES

NO

YES

Delete a pair (pairsplit -S)

YES

YES

YES

YES

YES

YES

Notes:

  1. The snapshot data must be consistent with P-VOL data and ready to use in the SI task.

    After issuing the pairsplit command for a Thin Image pair for which a consistency group is configured, verify that the status of all pairs in the Thin Image consistency group is PSUS or unpaired, and then execute the SI task. If you do not, the Thin Image snapshot data and P-VOL data when the storage system accepted the pairsplit command will not be consistent. For details about Thin Image pair status and operations, see the Hitachi Thin Image User Guide.

    For more information about ensuring the snapshot data is consistent with P-VOL data, see Ensuring snapshot data is consistent with P-VOL data.

  2. When the host accesses the Thin Image S-VOL, the Thin Image P-VOL data might be used to return a reply. For this reason, you cannot Quick Restore to exchange the SI P-VOL and S-VOL (which is the Thin Image P-VOL).