HP XP Continuous Access Software - Manual (Page 58)

58 Continuous Access XP for the XP1024/XP128
• Cancel button: Cancels settings made on the Add RCU pane, and closes the pane.
Figure 30 RCU Option pane
Use the RCU Option pane to set the options for the RCU.
• Minimum Paths: Minimum number of paths required for each RCU connected to the current MCU. The
default is one. If you specify a number that is larger than the number of paths set on the Register RCU
pane or the number of paths falls below this number (for example, failed path), an error occurs. When
errors occur, the MCU suspends all affected Continuous Access XP (and any mainframe) pairs to
prevent remote copy operations from adversely affecting performance due to the inadequate number
of paths. If the MCU contains Continuous Access XP pairs, which contain critical data for disaster
recovery, set minimum number of paths to one, so Continuous Access XP operations continue even if
there is only one path to an RCU. If you need high performance at the MCU, set minimum number of
paths to two or more (up to eight per CU image), depending on number of pairs managed by the
MCU.
CAUTION: If Continuous Access XP volume pairs are suspended because number of paths
dropped below this setting, the P-VOL fence-level pair option (see ” Creating Continuous Access XP
volume pairs (Paircreate) ” on page 81) determines whether Continuous Access XP Synchronous
P-VOLs are fenced (that is, all write operations are rejected).
• Maximum Initial Copy Activity: Number of concurrent initial copy operations: 4 Volumes or 16
Volumes. The default is 4 Volumes. Continuous Access XP initial copy activities can impact
performance of the main disk array, depending on amount of I/O activity and number of pairs
registered at one time. The setting of 4 Volumes limits impact of initial copy activities on disk array
performance. For example, if you set maximum initial copy activity to 4 Volumes and register five
Continuous Access XP pairs at one time, the MCU starts the first four pairs and will not start the fifth
pair until one of the first four pairs is synchronized (PAIR status). When you change the maximum
initial copy activity setting, the new setting applies to pairs created after the setting was changed, not
to existing pairs.
• RIO MIH Time: Time value for the remote I/O (RIO) missing interrupt handler (MIH), which is the wait
time until data transfer from the MCU to RCU is complete. The RIO MIH time must be from 10 to 100
seconds. The default is 15 seconds. This setting is available for both serial and Fibre Channel
interfaces.
• Path Blockade Watch: Time for monitoring blockade in Fibre Channel paths on the MCU side. The
path blockade watch must be from 0 to 45 seconds. The default is 40 seconds. This setting is
available for Fibre Channel interfaces only.
• Cancel button: Cancels the registering RCU operation.
• Set button: Sets the registering RCU operation with the option set on the RCU Option pane.