Hitachi VSP F1500 User Manual

Takeover-switch function
The control scripts activated by HA software are used by all nodes of a cluster
in exactly the same manner so they have no discrimination between primary
and secondary pair volumes (they just know the near and far disk in a pair).
Thus, the takeover command, when activated by a control script, must check
the combination of attributes of volumes possessed by the local and remote
nodes and determine the proper takeover action. The table below shows the
takeover actions.
Table 6-1 Near/Local and Far/Remote Volume Attributes and Takeover
Actions
Local node (Takeover node) Remote node
Takeover action
Volume
attribute
Fence and status
Volume
attribute
P-VOL status
SMPL - SMPL - Reject
P-VOL -
Nop-takeover
1
S-VOL - Unconformable
Unknown - Reject
P-VOL
(primary)
Fence == Data or
Status && pair
status == PSUE or
PDUB or MINAP ==
0
SMPL - Reject
P-VOL - Unconformable
S-VOL -
PVOL-Takeover
2
Unknown -
PVOL-Takeover
2
Others SMPL - Reject
P-VOL - Unconformable
S-VOL -
Nop-takeover
1
Unknown -
Nop-takeover
1
S-VOL
(secondary
)
Status == SSWS
(After
SVOL_SSUStakeove
r)
- -
Nop-takeover
1
Other than SSWS SMPL - Unconformable
P-VOL PAIR or PFUL
Swap-takeover
2
Others
SVOL-takeover
2
S-VOL - Unconformable
Unknown -
SVOL-takeover
2
Notes:
1. No action needed to allow local writes.
2. Required to allow local writes.
6-12
Data replication operations with CCI
Command Control Interface User and Reference Guide

Hitachi VSP F1500 Specifications

General

Brand	Hitachi
Model	VSP F1500
Category	Server
Language	English