Global-active device operations and Thin Image pair status

Ops Center High Availability User Guide
Version
10.8.x
File Size
3.9 MB
Audience
anonymous
Part Number
MK-99ADM003-10

The ability to perform a GAD pair operation depends on the GAD pair status and the HTI pair status.

The following tables show GAD operations and whether they can be performed (Yes, No) with the listed HTI status. The information assumes the required GAD status for the operation.

Table. GAD operations and HTI pair status, when the GAD P-VOL is shared

TI pair status

GAD pair operations

Create GAD Pairs

Suspend Pairs

Delete Pairs

Resync Pairs

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Forced deletion

P-VOL specified

S-VOL specified

SMPL(PD)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PAIR

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PSUS

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY(RS-R)

No4

impossible

impossible

Yes

No3

Yes

No4

No4

PSUE

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the P-VOL, only when the I/O mode is Local and the GAD pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the S-VOL, only when the I/O mode is Local and the GAD pair status of the S-VOL is SSWS.
  3. Cannot be used because, when you delete a GAD pair specifying the S-VOL, the P-VOL's virtual LDEV ID is also deleted, which makes it unusable as the HTI P-VOL.
  4. To continue resynchronizing the HTI pair, you must split the GAD pair.
Table. GAD operations and HTI pair status, when the GAD S-VOL is shared

TI pair status

GAD pair operations

Create GAD Pairs

Suspend Pairs

Delete Pairs

Resync Pairs

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Forced deletion

P-VOL specified

S-VOL specified

SMPL(PD)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PAIR

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PSUS

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY(RS-R)

No3, 5

No

No

No4

Yes

Yes

No5, 6

No6

PSUE

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the primary volume, only when the I/O mode is Local and the GAD pair status of the primary volume is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the secondary volume, only when the I/O mode is Local and the GAD pair status of the secondary volume is SSWS.
  3. To create a GAD pair, you must assign the GAD reserve attribute to the volume used as an S-VOL. Because the virtual LDEV ID of the volume to which the GAD reserve attribute is assigned is deleted, you cannot create a GAD pair by specifying the volume shared with HTI as the S-VOL of the pair.
  4. Cannot be used because, when you delete a GAD PAIR specifying the P-VOL, the S-VOL's virtual LDEV ID is also deleted, which makes it unusable as an HTI P-VOL.
  5. Cannot be used because the GAD pair's target volume is the same as the HTI pair's target volume.
  6. To continue resynchronizing the HTI pair, you must split the GAD pair.