Notes on executing RAID Manager commands

Nonstop Database, HiRDB Version 9 Disaster Recovery System Configuration and Operation Guide

4.3 Notes on executing RAID Manager commands

You use RAID Manager commands to perform operations on paired logical volume groups. A separate RAID Manager command is executed for each paired logical volume group. When executing RAID Manager commands, you must observe the conditions stated for each command as described in the RAID Manager documentation.

Organization of this section: (1) Executability of RAID Manager commands; (2) Period during which switchover to the remote site cannot be guaranteed

(1) Executability of RAID Manager commands

Whether a specific RAID Manager command can be executed depends on whether HiRDB is running. The following tables show the executability of RAID Manager commands.

Table 4-6 Executability of RAID Manager commands (1 of 2)

Command name	Function	Executability of RAID Manager command
Command name	Function	When HiRDB is running	When HiRDB is stopped
horcmshutdown	Stop RAID Manager	D	Y
horctakeover	Take control over paired logical volume groups	N	Y
paircreate	Generate a paired logical volume group	D	Y^#
pairsplit	Split a paired logical volume group	D	Y^#
pairresync	Re-synchronize a paired logical volume group	D	Y^#

Legend:: Y: Can be executed.; D: Differs depending on the condition. For details, see Table 4-7.; N: Cannot be executed.

#

Following command execution, switchover to the remote site cannot be guaranteed for a period of time. For details, see 4.3(2) Period during which switchover to the remote site cannot be guaranteed.

Table 4-7 Executability of RAID Manager commands (2 of 2)

Real Time SAN Replication processing method	Protection mode	Executability of RAID Manager command
All synchronous method	data	N
All synchronous method	never	Y^#
All asynchronous method	--	Y^#
Hybrid method	data	N
Hybrid method	never	Y^#

Legend:: Y: Can be executed.; N: Cannot be executed.; --: Not applicable

#: Following command execution, switchover to the remote site cannot be guaranteed for a period of time. For details, see 4.3(2) Period during which switchover to the remote site cannot be guaranteed.

(2) Period during which switchover to the remote site cannot be guaranteed

Following the execution of certain RAID Manager commands, a period occurs during which switchover to the remote site cannot be guaranteed. The following table shows the period during which switchover to the remote site cannot be guaranteed.

Table 4-8 Period during which switchover to the remote site cannot be guaranteed following RAID Manager command execution

Command name	Period during which switchover to the remote site cannot be guaranteed
Command name	Start	End
horcmshutdown	Immediately following command execution	Until RAID Manager restarts and enables a synchronization point
paircreate		Until the status of the paired logical volume group for which the command was executed becomes PAIR
pairsplit
pairresync