System Tunable Mapping: Tru64 UNIX to HP-UX 11i v2

Kernel Buffer Attributes
The following table shows the system tuning options for kernel buffer attributes:
Tru64 UNIX HP-UX Dynamic on HP-UX Description
bufcache
nbuf and bufages
(both deprecated on
HP-UX 11i v2)
No On HP-UX, sets the systemwide number of
file-system buffer and cache buffer headers,
The parameters are for backwards
compatibility and should be set to 0 because
the dynamic buffer cache is preferred.
ubc_minpercent dbc_min_pct
Yes The minimum percentage of physical
memory to be used by the dynamic buffer
cache.
ubc_maxpercent dbc_max_pct
Yes Maximum percentage of physical memory
for dynamic buffer cache.
ubc_borrowpercent
N/A N/A
Percentage of memory above which the UBC
is only borrowing memory from the virtual
memory.
ubc_minpercent (Tru64 UNIX) versus dbc_min_pct (HP-UX)
This parameter specifies the minimum percentage of physical memory to be used by the dynamic
buffer cache.
For Tru64 UNIX, the default value of this parameter is 10 percent. The maximum allowed value is
100 percent; the minimum value is 0 percent.
For HP-UX, the default value of this parameter is 5 percent of physical memory. The maximum allowed
value is 70 percent of physical memory, and the minimum is 1 percent of physical memory. The value
is further constrained in that it must be equal to or less than dbc_max_pct.
ubc_maxpercent (Tru64 UNIX) versus dbc_max_pct (HP-UX)
This parameter specifies the maximum percentage of physical memory to be used by the dynamic
buffer cache.
For Tru64 UNIX, the default value of this parameter is 100 percent. The maximum allowed value is
100 percent; the minimum allowed value is 0 percent.
For HP-UX, the default value of this parameter is 50 percent of physical memory. The maximum
allowed value is 90 percent of physical memory, and the minimum 1 percent of physical memory. The
value is further constrained in that it must be equal to or greater than dbc_min_pct.
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