swchunk

swchunk specifies the chunk size to be used for swap.

Acceptable Values:

Minimum
2048
Maximum
16384
Default
2048

Specify integer value. For more information, see Specifying Parameter Values.


Selecting an appropriate value for this parameter requires extensive knowledge of system internals. The value of swchunk should not be changed from the standard default value.


Description

swchunk defines the chunk size for swap. This value must be an integer power of two.

Swap space is allocated in "chunks", each containing swchunk blocks of DEV_BSIZE bytes each. When the system needs swap space, one swap chunks is obtained from a device or file system. When that chunk has been used and another is needed, a new chunk is obtained from a different device or file system, thus distributing swap use over several devices and/or file systems to improve system efficiency and minimize monopolization of a given device by the swap system.

Related Parameters

Total swap space is defined by:

swchunk * maxswapchunks * DEV_BSIZE

where DEV_BSIZE is 1024 bytes.

System-imposed maximum total swap space is approximately 34 Gbytes.

Additional Information