User`s guide

Release Notes
AA–RFBPE–TE 387372-005 Page 15
The solution is to restrict the maximum queue depth by setting
sd_max_throttle in the /etc/system file. The StorageWorks Solution
software has already throttled the queue depth back to 32 during the installation.
This will work fine for most environments. If you will be doing heavy I/O to 16
or more luns, you will need to set sd_max_throttle even lower. Edit your
/etc/system file, and change the sd_max_throttle entry in the
CPQhsg80 section. You must shutdown and reboot for the changes to take effect.
Set sd_max_throttle so that the number of active LUNs on the port times
sd_max_throttle is less than or equal to 256 (the maximum number of
queued requests for the port). For example, 16 busy LUNs on a port will require
a sd_max_throttle setting of 16 (256/16 = 16).
For more information, refer to the system (4) and sd (7D) man pages.
7.12 Manually Specifying Logical Geometry for a Large Storageset
There are two ways to configure a LUN’s logical geometry:
• Automatic Mode: This is the preferred way that is documented in Section
7.1. Storagesets up to 512 GB can be configured this way.
• Manual Mode: Manual configuration is described in this step. Note that the
maximum values are smaller when using manual mode. This reduces the
maximum LUN size to 256 GB when using manual mode. If you prefer to
use this mode, it is documented below.
The Solaris format command is used to label and partition a storageset before a
filesystem can be created on it. For large storagesets with a high number of large
disks the controller may specify a geometry that exceeds the parameters
supported by the format command. The maximum values supported by Solaris
(when manually configuring geometry) are:
• 32767 cylinders (including 2 alternate cylinders)
• 64 heads
• 256 sectors per track
The symptoms of exceeding these maximums will vary.
Exceeding 64 heads will cause newfs to abort with the following error message:
There is no block size that can support this disk
Exceeding 32767 cylinders will cause format to report an incorrect size (much
higher or lower than the actual size of the storageset).