This section provides instructions for setting the system parameters
for AMCC adapters on a SUN host.
- Type cd/etc to change to the /etc subdirectory.
- Backup the system file in the subdirectory.
- Edit the system file and set the following parameters for servers
with configurations that use AMCC adapters:
Note: To
configure the AMCC adapters see the EZ Fibre Configuration Utility at:
http://www.amcc.com.
- sd_max_throttle
- This sd_max_throttle parameter specifies the maximum number of commands
that the sd driver can queue to the host adapter driver. The default value
is 256, but you must set the parameter to a value less than or equal to a
maximum queue depth for each LUN connected. Determine the value by using the
following formula: 256 ÷ (LUNs per adapter) where LUNs
per adapter is the largest number of LUNs assigned to a single adapter.
To
set the sd_max_throttle parameter for the storage unit LUNs in this example,
you would add the following line to the /etc/system file: set sd:sd_max_throttle=5
- sd_io_time
- This parameter specifies the timeout value for disk operations. Add the
following line to the /etc/system file to set the sd_io_time parameter for
the storage unit LUNs:set sd:sd_io_time=0x78
- sd_retry_count
- This parameter specifies the retry count for disk operations. Add the
following line to the /etc/system file to set the sd_retry_count parameter
for the storage unit LUNs: set sd:sd_retry_count=5
- maxphys
- This parameter specifies the maximum number of bytes that you can transfer
for each SCSI transaction. The default value is 126976 (124 KB). If the I/O
block size that you requested exceeds the default value, the request is broken
into more than one request. You should tune the value for the application
requirements. For maximum bandwidth, set the maxphys parameter by adding the
following line to the /etc/system file: set maxphys=1048576 (1 MB)
Note: Do not set the value for maxphys greater than 1048576
(1 MB). Doing so can cause the system to hang.