HP XP P9500 Storage - Manual (Page 25)

Table 12 Order of starting initial copy being performed (continued)
Remarks Value set for Priority P-VOL Order of starting initial
copy
Continuous Access Synchronous pair
for which initial copy is newly
instructed to be performed 1 LUN 11 5
Continuous Access Synchronous pair
for which initial copy is newly
instructed to be performed 2 LUN 10 6
The Priority is determined within the range of the number of initial copy operations performed at
the same time. Therefore, until the first initial copy operations complying with the order of the
Priority are completed, the additional initial copy operations are not started.
Planning data paths
A data path must be designed to adequately manage all possible amounts of data that could be
generated by the host and sent to the P-VOL and S-VOL.
Amount of bandwidth required
Sufficient bandwidth must be present to handle data transfer of all workload levels. The amount
of bandwidth required for your Continuous Access Synchronous system is based on the amount of
I/O sent from the host to the primary volume. You determine required bandwidth by measuring
write-workload. Workload data is collected using performance monitoring software. Consult your
HP account team for more information.
Fibre Channel requirements
The primary and secondary systems must be connected using multimode or single-mode optical
fibre cables.
•
For distances up to 1.5 km (4,920 feet), multimode shortwave Fibre Channel interface cables
are used. For distances between 0.5 km to 1.5 km, with at least one switch are required you
can use a maximum of two switches.
•
For the distances from 1.5 km to 10 km, (4,920 feet to 6.2 miles) single mode longwave
optical fibre cables are required.
•
For distances from 10 km to 30 km (6.2 to 18.6 miles), single-mode longwave Fibre Channel
interface cables with up to two switches are required.
•
For distances greater than 30 km. Approved third-party channel extender products and
telecommunications lines are required. Continuous Access Synchronous operations typically
do not extend past 30 km.
With Fibre Channel connections, you can use the switches as ordinary switch connections. No
special settings are required for the P9500.
Direct connections up to 10 km with single-mode longwave Fibre Channel interface cables are
supported. Link speed determines the maximum distance you can transfer data and still achieve
good performance. The following shows link speed and maximum distance for best performance.
Table 13 Link speed, maximum distance to 10 km
Maximum distance for best performance Link speed
10 km 1 Gbps
6 km 2 Gbps
Planning data paths 25