IBM z/OS - Manual (Page 45)

45
Continuous Availability Recommended Confi guration for
Parallel Sysplex
Note: z990 will attach to 9037-001 or 9037-002. Service for 9037-001
will be discontinued at the end of 2003.
Components and assumptions
• Two Coupling Facilities; at least one external or else
using System-Managed CF Structure Duplexing
• Two Sysplex Timers
• Two z/OS or OS/390 servers with redundant backup
capacity
• Two links from each CF to each image
• Two hardware management consoles
• Two ESCON or FICON Directors with cross-connected
disks
• Dual electrical power grids
• Cloned OS/390 images, latest available software levels
• Automation capabilities for recovery/restart
• Critical data on RAID and/or mirrored disks
Key attributes can include
• No single point of failure
• Fast, automatic recovery
– CF: rebuild in surviving CF
– CEC, z/OS, OS/390: restart subsystems on surviving
image
– TM/DBMS: restart in place
• Surviving components absorb new work
• No service loss for planned or unplanned outages
• Near unlimited, plug-and-play growth capacity
ESCON/FICON Express Channels
z/OS z/OS
Internal Coupling
Facility
Dedicated (External)
Coupling Facility
z900 Model 100
9674, 9672 R06,
or z800 Model 0CF
ICF
IC
z990
with CFs only
Sysplex Timers