After you attach your DS8000® to
a Hewlett-Packard 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:
- Enter scsimgr
set_attr -D /dev/rdsk/$dsksf -a max_qdepth=21 where
/dev/rdsk/$dsksf is
the device node.
- To locate the device node, enter the ioscan
command.
- To save the update after rebooting, complete
the following steps:
- Enter scsimgr save_attr -D /dev/rdsk/$dsksf
-a max_qdepth=21 where
/dev/rdsk/$dsksf is
the device node.
- To locate the device node, enter the ioscan
command.
- To update or save the queue depth by
driver level, complete the following steps:
- Enter scsimgr [set/save]_attr -N /escsi/$driver
-a max_qdepth=21 where
/escsi/$driver is
the disk driver. For example, /escsi/esdisk.