Paging space file, commands, and options
The /etc/swapspaces file specifies the paging spaces and the attributes of the paging spaces.
A paging space is added to the /etc/swapspaces file when it is created by the mkps command, and a paging space is removed from the /etc/swapspaces file when it is deleted by the rmps command. The paging space attributes in the file are modified by the chps -a command or the chps -c command. Files using a previous format (where there are no attributes for checksum size and automatic swap-on in the stanzas) continue to be supported. If the paging space size is too large, you can subtract logical partitions from the paging space without rebooting using the chps -d command.
The following commands are used to manage paging space:
| Item | Description |
|---|---|
| chps | Changes the attributes of a paging space. |
| lsps | Displays the characteristics of a paging space. |
| mkps | Adds an additional paging space. The mkps command uses the mklv command with a specific set of options when creating a paging space logical volume. To create NFS paging spaces, the mkps command uses the mkdev command with a different set of options. For NFS paging spaces, the mkps command needs the host name of the NFS server and the path name of the file that is exported from the server. |
| rmps | Removes an inactive paging space. |
| swapoff | Deactivates one or more paging space without rebooting the system. Information in the paging space is moved to other active paging space areas. The deactivated paging space can then be removed using the rmps command. |
| swapon | Activates a paging space. The swapon command is used during early system initialization to activate the initial paging-space device. During a later phase of initialization, when other devices become available, the swapon command is used to activate additional paging spaces so that paging activity occurs across several devices. |
The paging type option is required for all logical volume paging spaces.
The following options are used to maximize paging performance with a logical volume:
- Allocate in the middle of the disk to reduce disk arm travel
- Use multiple paging spaces, each allocated from a separate physical volume.