HP StorageWorks XP Remote Web Console Software User Manual
Page 109
If the initial copy operation is performed witht he default value of Round Trip Time instead of the
appropriate value, it may take an unexpectedly long time to complete the initial copy operation.
You may specify 1 ms to 500 ms for the Round Trip Time. You can use the following formula to
figure out the value of Round Trip Time.
The value of Round Trip time =
round trip time between MCU RCU x 2
*
+ initial copy response time (ms)
*
: data transfer between MCU and RCU involves two response sequences in one command issuance. Therefore, you
need to double the round trip time between MCU and RCU.
For the round trip time between MCU and RCU, ask your carrier, or use a ping command and etc.
to measure the time. If the connections between the MCU and RCU are short and do not use telecom
provider circuits between MCU and RCU, specify 1.
Initial copy response time is the response time required for multiple initial copy operations. You
can use the following formula to get the initial copy response time. To get the time, you should use
the following values: the initial copy pace, the maximum number of maximum initial copy volumes,
the speed of the line between MCU and RCU, and the number of lines.
Initial copy response time (ms) = (1[MB] / “Speed of line between MCU RCU[MB/ms]
(*1)
”) x
(“initial copy pace”
(*2)
/ 15) x (“max number of maximum initial copy VOLs
(*3)
” / “Number of
lines between MCU RCU”
(*4)
)
*1
When you connect MCU with RCU without lines etc., specify 0.17[MB/ms] in Speed of line
between MCU and RCU.
*2
For initial copy pacein the formula above, see
“Initial Copy Pace for Calculating the Initial Copy
*3
For the maximum number of maximum initial copy volumes, use the value set up per storage
system. The default is 64.
*4
Even if Max number of maximum initial copy VOLs / Number of lines between MCU-RCU is
larger than 16, specify Max number of maximum initial copy VOLs / Number of lines between
MCU-RCU as 16.
Table 41 Initial Copy Pace for Calculating the Initial Copy Response Time
Perform Initial Copy and Update Copy at a Time
Perform Initial Copy Only
Operation
Initial Copy Pace Specified
ath the Time of Pair Creation
9 to 15
Initial Copy Pace Specified
at the Time of Pair Creation
is 1 to 8
8
Initial copy pace specified
at the time of pair creation
Initial copy pace specified
at the time of pair creation
Remote Web Console
8
Initial copy pace specified
at the time of pair creation
Initial copy pace specified
at the time of pair creation
Business Continuity Manager
8
Initial copy pace specified
at the time of pair creation
Initial copy pace specified
at the time of pair creation
PPRC command
(TSO/ICKDSF) and CU
emulation type = 3990
8
15
PPRC command
(TSO/ICKDSF) and CU
1
1
emulation type = 2105 or
2107
RCU Operations 109