Advanced Topics › Communication Methods › CTCDASD
CTCDASD
The CTCDASD communication method is a combination of the preceding two methods using the DASD or coupling facility structure control file as a backup.
Benefits
- Allows the MIMplex systems to be any combination of sysplexed and non-sysplexed images
- Provides high performance, especially for CA MII sites
- Provides backup master system capability in case of master system failure
- Defines backup DASD or coupling facility structure control file in case of CTC failure or if there are no available backup masters
- Is not subject to contention delays associated with DASD I/O when VCF is in use
Requirements
- A 3380/3390-type DASD volume accessible by all systems participating in the MIMplex.
- 3088 or extended mode ESCON CTC devices connecting at least one system to all others in the MIMplex.
- At least one CA MIM address space defined to manage the virtual control file (VCF).
- A coupling facility list structure (optional).
- If using coupling facility structure control files, all MIMplex systems must be in the same parallel sysplex.
