Compaq Infortrend manual Number of Tags Reserved for each Host-LUN Connection

From the main menu, select “View and Edit Configuration Parameters,” “Host-side SCSI Parameters,” then press [ENTER]. Choose “Max Number of Concurrent Host-LUN Connection,” then press [ENTER]. A list of available selections will appear. Move cursor bar to an item, then press [ENTER]. Choose Yes in the dialog box that follows to confirm your setting. The default setting is “4.”

Number of Tags Reserved for each Host-LUN Connection:

Each "nexus" has "32" (the default setting) tags reserved. When the host computer sends 8 of I/O tags to the controller, and the controller is too busy to process all, the host might start to send less than 8 tags during every certain period of time since then. This setting ensures that the controller will accept at least 32 tags per nexus. The controller will be able to accept more than that as long as the controller internal resources allow - if the controller does not have enough resources, at least 32 tags can be accepted per nexus.

Choose “Host-side SCSI Parameters,” then press [ENTER]. Choose “Number of Tags Reserved for each Host-LUN Connection,” then press [ENTER]. A list of available selections will appear. Move cursor bar to an item, then press [ENTER]. Choose Yes in the dialog box that follows to confirm the setting.

Advanced Configurations 9-12