IBM DS8000 manual DS CLI command flow, Secure sockets, TCP/IP ports

Open systems
host
CLI script
CS CLI
ESS CLI software
Network interface
CS Server A	CS Server B
CS Client	CS Client
Cluster 1	Cluster 2
ESS 800

Figure 11-1 Command flow for ESS 800 Copy Services commands

A CS server is now able to manage up to eight F20s and ESS 800s. This means that up to sixteen clusters can be clients of the CS server. All FlashCopy and remote copy commands are sent to the CS server, which then sends them to the relevant client on the relevant ESS.

DS CLI command flow

Scripts that invoke DS CLI commands issue those commands to the installed DS CLI software on the open systems host. If the command is intended for an ESS 800 volume, then the DS CLI software sends it to the CS server on the ESS 800. If, however, the command is intended for a DS8000, the command is issued to the CLI interpreter of the Storage Hardware Management Console (S-HMC). The S-HMC then interprets the command and issues it to the relevant server in the relevant DS8000 using the redundant internal network that connects the S-HMCs to the DS8000.

Secure sockets

All DS CLI traffic is encrypted using SSL (secure sockets layer). This means that all traffic between the host server that is running the DS CLI client and the DS CLI server (for example, the S-HMC or the ESS 800 cluster) is secure, including passwords and userids.

TCP/IP ports

DS CLI servers (such as an S-HMC) use a fixed number of TCP/IP ports to listen on. These ports are listed in Chapter 9, “Configuration planning” on page 157. This is important for planning considerations, where a firewall may exist between the client and the server.

Chapter 11. DS CLI 235