HP StorageWorks HSG80 Enterprise Modular Storage RAID Array Fibre Channel Solution Software V8.8 for Sun Solaris Release Notes (AA-RV1SA-TE, March 2005)

Host Operating System Notes
42 HSG80 Enterprise Modular Storage RAID Array Fibre Channel Solution Software V8.8 for Sun
Solaris Release Notes
you are doing heavy I/O to 16 or more LUNs, you need to set sd_max_throttle
even lower. Edit your /etc/system file, and change the sd_max_throttle entry
in the CPQfcraid 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 requires a
sd_max_throttle setting of 16 (256/16 = 16).
For more information, see the system (4) and sd (7D) man pages.
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 method. Storagesets up to 1.024 TB
can be configured this way.
■ Manual Mode: When using manual mode, maximum values are smaller,
which reduces maximum LUN size to 256 GB. If you prefer to use manual
mode, it is documented below.
The Solaris
format command is used to label and partition a storageset before a
file system 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:
■ 32,767 cylinders (including 2 alternate cylinders)
■ 64 heads
■ 256 sectors per track
The symptoms of exceeding these maximums will vary.
Exceeding 64 heads causes newfs to abort with the following error message:
There is no block size that can support this disk
Exceeding 32767 cylinders causes format to report an incorrect size (much higher
or lower than the actual size of the storageset).