Setting the queue depth for an HP-UX host

After you attach your DS8000® to a Hewlett Packard Enterprise server that is running the HP-UX operating system, you can set the queue depth by device level or globally.

Before you begin

Before you set the queue depth, you must attach the host system to a DS8000.

Procedure

To set the queue depth for all classes of HP-UX, use the following formula:

256 ÷ maximum number of LUNs = queue depth
Note: For optimum performance, monitor configurations with greater than 256 LUNs and adjust the queue depth.

  • To update and activate the queue depth by device immediately, complete the following steps:
    1. Enter scsimgr set_attr -D /dev/rdsk/$dsksf -a max_qdepth=21 where /dev/rdsk/$dsksf is the device node.
    2. To locate the device node, enter the ioscan command.
  • To save the update after rebooting, complete the following steps:
    1. Enter scsimgr save_attr -D /dev/rdsk/$dsksf -a max_qdepth=21 where /dev/rdsk/$dsksf is the device node.
    2. To locate the device node, enter the ioscan command.
  • To update or save the queue depth by driver level, complete the following steps:
    1. Enter scsimgr [set/save]_attr -N /escsi/$driver -a max_qdepth=21 where /escsi/$driver is the disk driver. For example, /escsi/esdisk.