Tunable Kernel Parameters

Memory Paging Subsystem
Memory Paging Parameter Summary
Chapter 7
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Memory Paging Parameter Summary
Variable Page Size Parameter Summary
Memory Paging allocate_fs_swapmap Enable or disable preallocation of file system swap space
when swapon() is called as opposed to allocating swap
space when malloc() is called. Enabling allocation
reduces risk of insufficient swap space and is used
primarily where high availability is important. Manpage:
allocate_fs_swapmap (5).
Memory Paging max_mem_window Maximum number of group-private 32-bit shared memory
windows. Manpage: max_mem_window (5).
Memory Paging nswapdev Maximum number of devices, system-wide, that can be
used for device swap. Set to match actual system
configuration. Manpage: nswapdev (5).
Memory Paging nswapfs Maximum number of mounted file systems, system-wide,
that can be used for file system swap. Set to match actual
system configuration. Manpage: nswapfs (5).
Memory Paging remote_nfs_swap Enable or disable swap to mounted remote NFS file
system. Used on cluster clients for swapping to
NFS-mounted server file systems. Manpage:
remote_nfs_swap (5).
Memory Paging swapmem_on Enable or disable pseudo-swap allocation. This allows
systems with large installed memory to allocate memory
space as well as disk swap space for virtual memory use
instead of restricting availability to defined disk swap
area. Manpage: swapmem_on (5).
Memory Paging swchunk Amount of space allocated for each chunk of swap area.
Chunks are allocated from device to device by the kernel.
Changing this parameter requires extensive knowledge of
system internals. Without such knowledge, do not change
this parameter from the normal default value. Manpage:
swchunk (5).
Memory Paging allocate_fs_swapmap Enable or disable preallocation of file system swap space
when swapon() is called as opposed to allocating swap
space when malloc() is called. Enabling allocation
reduces risk of insufficient swap space and is used
primarily where high availability is important. See
allocate_fs_swapmap (5).
Memory Paging:
Size
vps_ceiling Maximum system-selected page size (in KB) if the user
does not specify a page size. Manpage: vps_ceiling (5).
Memory Paging:
Size
vps_chatr_ceiling Maximum page size a user can specify with the chatr
command in a program. Manpage: vps_chatr_ceiling (5).