Note the use of swap -l to display the individual swap areas. The first column is the type of swap space. A value of hold indicates swap space that is reserved by the kernel for future use for processes that may not have used all the swap space needed. This swap space is not allocated to a specific device or file system. For file system swap areas, this field contains the maximum number of 1-kilobyte blocks available from the file system as swap space.
Space is used first from swap areas with the lowest priority number.
When you add a new swap area, you may specify a priority. This feature allows you to assign a higher priority to the faster swap areas so that slower areas will be used only when the primary swap areas become full. Swap areas of the same type with the same priority are interleaved. The system will first use all raw swap partitions, then use file system swap as needed. Only the root user may run swapinfo , but there is a patch available to allow non-root users to execute swapinfo .