HP-UX System Administrator's Guide: Overview

a disk drive and are using legacy device special files, refer to
the scsimgr(1M) manpage for assistance with remapping the
device special file to the new device. The scsimgr command
to do this is replace_leg_dsf.
For More Information on the Next Generation Mass Storage Stack
The following resources contain much more information on the components of the
Next Generation Mass Storage Stack:
• Technical White Paper: The Next Generation Mass Storage Stack HP-UX 11i v3
• The following manpages:
— scsimgr(1M)
— io_redirect_dsf(1M)
— insf(1M), lssf(1M), mksf(1M), rmsf(1M)
— iobind(1M), iofind(1M), ioscan(1M)
— intro(7)
Managing HP-UX Swap Space
Swap space is where HP-UX stores unneeded pages of memory from running processes,
a process called virtual memory paging (or simply paging) because the chunks of data
moved in and out of physical RAM are called pages. This enables HP-UX to use much
more memory than physically exists on a server.
Types of Swap Space
There are three types of swap space used for paging operations:
• Device Swap
• File System Swap
• Pseudo Swap
Device Swap
Swap space is initially allocated when you configure your disks. Device swap space
occupies a logical volume or disk partition that is typically reserved expressly for
paging purposes. This space may also be configured as a dump area but doing so has
implications for memory dump integrity if a crash occurs. See “Using a Device for Both
Paging and Dumping (System Recovery Time)” (page 99). Because, when HP-UX is
running, the device is used exclusively for paging, you cannot also store files on it.
Storage on HP-UX 69