SSARAID Command Attributes
When using the ssaraid command, you can specify the following types of attribute:
vRAID array Creation and Change attributes
vRAID array Change attributes
vPhysical Disk Drive Change attributes
vAction attributes
RAID Arrays Creation and Change Attributes
This section describes the creation and change attributes that you can use for:
vAll RAID arrays
vRAID-1, RAID-5, and RAID-10 arrays only
vRAID-1 and RAID-10 arrays only
vRAID-5 arrays only
vRAID-10 arrays only
Creation and Change Attributes for All RAIDArrays
Youcan specify the following attributes with the -a option when you are using the
ssaraid command with the -C or -H option to create or change a RAID array:
allow_page_splits=true/false (default=true)
With the attribute set to true:
When large blocks of data are sent to an array,those blocks can be internally
split into smaller,4096-byte blocks that can then be written in parallel to the
member disk drives of the array.This action greatly improves the performance
of write operations to the array,although the blocks are not written sequentially
to the member disk drives.
With the attribute set to false:
The blocks of data are written sequentially to the member disk drives of the
array.This action can have a negative effect on the performance of write
operations to the array.The sequence in which the data is written to the array
might be critical to the application program that is using the data, if an error
occurs during the write operation.
fastwrite=on/off (default=off)
This attribute enables and disables the fast-write cache.
When using the fast-write cache, you can use the following attributes to control the
operation of the cache:
fw_start_block (default=0)
See the definition for fw_end_block .
fw_end_block (default=array size)
This attribute and the fw_start_block attribute control the range of blocks for
which the fast-write cache is enabled. Write operations that are outside the
default range of 0 through array size write data directly to the array,and do not
use the fast-write cache.
244 User’s Guide and Maintenance Information