Compaq Infortrend Manuale Utente

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.”

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.