HP StorageWorks XP Remote Web Console Software - Manual (Page 89)

TrueCopy for z/OS user guide 89
required for the initial copy operation is large, it means that the workload of the update copy is relatively
high. Therefore, the copy pace of the initial copy will be slowed. When the time is relatively small, the
copy pace will speed up to the specified value. In this way, we can curb the influence of the exclusive line
use in the initial copy operation on the host performance.
NOTE: This option is available only in the case of TCz pairs (In the case of TCzA pairs, this option value
is invalid).
The default value of Round Trip Time is 1 ms. You may specify 1 ms to 500 ms. You can use the following
formula to figure out the Round Trip Time.
For Round Trip Time between MCU and RCU, please ask your carrier, or use a ping command and etc. to
measure the time. If you do not use lines etc. 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 max number of initial copy VOLs, the speed of the line between MCU
and RCU, and the number of lines.
Round Trip time = Round Trip Time between MCU-RCU x 2
1
+ Initial Copy response time (ms)
1. A 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-RCU.
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 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 pace” in the formula above, see
Table 18 .
3. For the maximum number of initial copy volumes, see ” Initial Copy Operations ” on page 27. The default is 64.
4. Even if “Max number of initial copy VOLs”/“Number of lines between MCU-RCU” is larger than 16, specify “Max number of
initial copy VOLs”/“Number of lines between MCU-RCU” as 16.
Table 18 Initial Copy Pace for Calculating The Initial Copy Response Time
Perform Initial
Copy Only
Perform Initial Copy and Update Copy
at a Time
Initial Copy Pace
Specified at the
Time of Pair
Creation is 1 to 8
Initial Copy Pace
Specified at the
Time of Pair
Creation is 9 to 15
Operation Storage Navigator Initial copy pace
specified at the time
of pair creation
Initial copy pace
specified at the time
of pair creation
8
Business Continuity
Manager
Initial copy pace
specified at the time
of pair creation
Initial copy pace
specified at the time
of pair creation
8
PPRC command
(TSO/ICKDSF) and
CU emulation
type=3390
Initial copy pace
specified at the time
of pair creation
Initial copy pace
specified at the time
of pair creation
8
PPRC command
(TSO/ICKDSF) and
CU emulation
type=2150
15 1 8 1