Share an iSCSI HBA among multiple hosted servers

A single iSCSI HBA for iSeries™ may be able to handle the workload for several servers that do not require high bandwidth for the SCSI and virtual Ethernet LAN traffic. For example, you can share an iSCSI HBA for iSeries among several development and test servers if their workload is light.

There are limits to the number of storage and virtual Ethernet paths that an iSCSI HBA can support. Each active server storage path will use a file server resource in the network server host adapter (NWSH) object that corresponds to the iSCSI HBA. Likewise, each active server virtual Ethernet path will use a virtual Ethernet resource in the NWSH object. There is a limit to the number of file server and virtual Ethernet resources supported by a particular NWSH, which limits how many active servers can use the NWSH.

To see the NWSH file server and virtual Ethernet resource limits using iSeries Navigator, follow these steps:

1. Expand Integrated Server Administration.
2. Expand iSCSI Connections.
3. Select Local Host Adapters.
4. Right-click a NWSH from the list available.
5. Select Properties.
6. Click on the Resource Usage tab.
7. The table shows the active servers that are currently using the NWSH and the file server and virtual Ethernet resources that they are currently using. Below the table it shows how many file server and virtual Ethernet resources are still available for use by inactive servers and the total number of file server and virtual Ethernet resources that the NWSH supports.
8. Click Cancel on the NWSH properties panel to close the panel.

If you want to use a CL command, see the WRKDEVD or DSPDEVD commands.

There is also a less defined practical limit to the number of servers that an iSCSI HBA can support. The practical limit is determined by the available iSCSI HBA bandwidth and the workload that is being run through the iSCSI HBA. The practical limit will most likely limit how many hosted systems the iSCSI HBA can support before the file server and virtual Ethernet resource limits described above are reached. The practical limits will depend on your particular server configurations and workloads.