HP XP P9500 Storage - Manual (Page 34)

Table 17 Order of starting initial copy being performed
Remarks Value set for Priority M-VOL Order of starting initial
copy
Cnt Ac-S Z pair for which initial copy
is already instructed to be performed 1 LDEV 02 1
Cnt Ac-S Z pair for which initial copy
is already instructed to be performed 2 LDEV 00 2
Cnt Ac-S Z pair for which initial copy
is already instructed to be performed 3 LDEV 01 3
Cnt Ac-S Z pair for which initial copy
is already instructed to be performed 4 LDEV 03 4
Cnt Ac-S Z pair for which initial copy
is newly instructed to be performed 1 LDEV 11 5
Cnt Ac-S Z pair for which initial copy
is newly instructed to be performed 2 LDEV 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 M-VOL and R-VOL. This section provides requirements and
planning considerations for the following key elements of the data path:
•
“Amount of bandwidth required” (page 34)
•
“Fibre Channel requirements” (page 34)
•
“Supported data path configurations” (page 35)
•
“Planning ports” (page 37)
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 Z system is based on the amount
of I/O sent from the host to the main volume. You determine required bandwidth by measuring
write-workload. Workload data is collected using RMF data. Consult your HP account team for
more information.
Fibre Channel requirements
The main and remote disk arrays must be connected using multimode or single-mode optical fiber
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 fiber 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 Z operations typically
do not extend past 30 km.
34 Planning for Continuous Access Synchronous Z