Filter
Top Products
Chapter 9. Configuration planning 183
Figure 9-14 DDM to DA Mapping (4-way model)
Model 922 can have eight DA pairs and 20 disk enclosure pairs.
Therefore, a 512 DDMs configuration is a well-balanced configuration (all eight DA pairs have
64 DDMs).
When you have the maximum number of DDMs (640 DDMs), DA pair 0 and 1 have 128
DDMs, and DA pairs 2 through 7 have 64 DDMs.
9.5 Data migration planning
When migrating data, the migration objectives should be clearly defined. Use the following
key questions to define your generic migration environment:
Why is the data migrating?
How much data is migrating?
How quickly must the migration be performed?
What duration of service outage can be tolerated?
Is the data migration to or from the same type storage, for example from an ESS Model
800 to a DS8000?
What resources are available for the migration?
After answering these questions, you will be in a position to choose the appropriate tools and
utilities, such as standard operating system mirroring, basic commands, software packages,
remote copy technologies, and migration appliances to achieve your data migration
objectives.
DDM to DA Mapping -- 4-way
0/1
1/0
3/2
2/3
2
2
0
0
6
6
4
4
7
7
5
5
3
3
1
1
2
2
0
0
4/5
5/4
7/6
6/7
S0
S1
disk enclosure pair
installation sequence
0/1
2
disk enclosure pair
(32 DDMs can be installed
2 means to attach to DA pair 2)
I/O drawer
(0/1 means device adapters
for DA pair 0 and 1)
S0
Server
(0 means server 0)
Base Frame
Expansion
Frame 1
Expansion
Frame 2