buffer cache information Post: 19540

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LEARN ABOUT HPUX

vxfs_bc_bufhwm

vxfs_bc_bufhwm(5)						File Formats Manual						 vxfs_bc_bufhwm(5)

NAME

       vxfs_bc_bufhwm - VxFS buffer cache high water mark(determines the VxFS buffer cache size)

SYNOPSIS

VALUE

       Specify an integer value.

   Minimum
       6144 KB

   Maximum
       None

   Default
       0

DESCRIPTION

       VxFS  maintains a buffer cache in the kernel for frequently accessed file system metadata in addition to the HP-UX kernel buffer cache that
       caches the file data.  tunable parameter determines the size of the VxFS buffer cache (the maximum amount of memory that  can  be  used	to
       cache VxFS metadata).

       The default value computed based on the amount of system memory ensures good system performance across a wide range of applications.

       The value of is specified in kilobytes. To improve performance during application loads that cause frequent file system metadata changes on
       the system (for example, a high rate of file creation or deletion, or accessing large directories), change the value of

   Notes
       Use the command to monitor buffer cache statistics and inode cache usage.

EXAMPLES

       Set the maximum of size of buffer cache at 300000:

WARNINGS

       All HP-UX kernel tunable parameters are release specific.  This parameter may be removed or its meaning may change in the  future  releases
       of HP-UX.

       Installation  of  optional  kernel  software, from HP or other vendors, may cause changes to tunable parameter values.  After installation,
       some tunable parameters may no longer be at the default or recommended values.  For information about the effects of installation  on  tun-
       able  values,  consult  the documentation for the kernel software being installed.  For information about optional kernel software that was
       factory installed on your system, see at

SEE ALSO

       kctune(1M), vxfsstat(1M), vx_maxlink(5), vx_ninode(5), vxfs_ifree_timelag(5).

							     Tunable Kernel Parameters						 vxfs_bc_bufhwm(5)

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