TI pair
status
GAD pair operations
Create
GAD
Pairs
Suspend Pairs
Delete Pairs
Resync Pairs
P-VOL
selected
S-VOL
selected
P-VOL
selected
1
S-VOL
selected
2
Forced
deletion
P-VOL
selected
S-VOL
selected
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
.
When creating a GAD pair, the reservation attribute is set on the volume to become the S-VOL.
Doing this removes the virtual LDEV ID of this volume, which makes it unusable as an HTI pair
volume.
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 the 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.
Related topics
•
Use cases for pairing GAD volumes with SI or HTI
Backing up GAD pair volumes with ShadowImage (SI) or Thin Image (HTI)
provides further protection for GAD data, in the following ways:
•
When the GAD pair is resynchronized, pair status changes to COPY. While
in this status, S-VOL consistency is temporarily lost. You can protect data
when in COPY status by pairing the S-VOL with SI or HTI before
resynchronizing the GAD pair.
•
Though data in a blocked GAD pair is inconsistent, host activity can
continue with the P-VOL and/or S-VOL. Therefore, before correcting the
failure by forcibly deleting the pair, you should pair the volumes with SI
or HTI.
•
The SI and HTI pairs can then be copied, and the copies used for other
purposes.
Data Retention Utility
You can create a GAD pair using volumes that have been assigned the Data
Retention Utility access attribute.
•
When you create or resynchronize a GAD pair, the access attribute set for
the P-VOL is copied to the S-VOL.
•
If you change the access attribute when GAD status is Mirrored or
Mirroring, make sure to set the access attribute to both the P-VOL and S-
VOLs.
System requirements
2-17
Hitachi Virtual Storage Platform G1000 Global-Active Device User Guide
Summary of Contents for G1000
Page 8: ...Index viii Hitachi Virtual Storage Platform G1000 Global Active Device User Guide ...
Page 14: ...xiv Preface Hitachi Virtual Storage Platform G1000 Global Active Device User Guide ...
Page 238: ...9 18 Troubleshooting Hitachi Virtual Storage Platform G1000 Global Active Device User Guide ...
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