IBM SG24-5131-00 manual Cluster Disks, SSA Disks, Target-mode Scsi, Target-mode SSA

Models: SG24-5131-00

1 240
Download 240 pages 48.89 Kb
Page 34
Image 34

2a PCI Multiport Async Card is required in an S7X model, no native ports

3only one serial port available for customer use, i.e. HACMP

In case the number of native serial ports doesn’t match your HACMP cluster configuration needs, you can extend it by adding an eight-port asynchronous adapter, thus reducing the number of available MCA slots, or the corresponding PCI Multiport Async Card for PCI Machines, like the S7X model.

Target-mode SCSI

Another possibility for a non-TCP/IP network is a target mode SCSI connection. Whenever you make use of a shared SCSI device, you can also use the SCSI bus for exchanging heartbeats.

Target Mode SCSI is only supported with SCSI-2 Differential or SCSI-2 Differential Fast/Wide devices. SCSI/SE or SCSI-2/SE are not supported for HACMP serial networks.

The recommendation is to not use more than 4 target mode SCSI networks in a cluster.

Target-mode SSA

If you are using shared SSA devices, target mode SSA is the third possibility for a serial network within HACMP. In order to use target-mode SSA, you must use the Enhanced RAID-5 Adapter (#6215 or #6219), since these are the only current adapters that support the Multi-Initiator Feature. The microcode level of the adapter must be 1801 or higher.

2.3 Cluster Disks

This section describes the various choices you have in selecting the type of shared disks to use in your cluster.

2.3.1 SSA Disks

The following is a brief description of SSA and the basic rules to follow when designing SSA networks. For a full description of SSA and its functionality, please read Monitoring and Managing IBM SSA Disk Subsystems, SG24-5251.

SSA is a high-performance, serial interconnect technology used to connect disk devices and host adapters. SSA is an open standard, and SSA specifications have been approved by the SSA Industry Association and also as an ANSI standard through the ANSI X3T10.1 subcommittee.

16 IBM Certification Study Guide AIX HACMP

Page 34
Image 34
IBM SG24-5131-00 manual Cluster Disks, SSA Disks, Target-mode Scsi, Target-mode SSA