NFS Performance Tuning for HP-UX 11.0 and 11i Systems

nfs performance tuning for hp-ux 11.0 and 11i systems page 116
Notes:
Page 116July 22, 2002
Copyright 2002 Hewlett- Packard Company
Kernel Parameter Recommendations
(part 1)
kernel
parameter
tuning
Variable Description Def Recommend
4096128
The size of the pool of locks
used to control access to
buffer cache data structures
bufcache_hash_locks
1 (enable)0
Enable/disable immediate
disk reporting
default_disk_ir
25 (client)
50 (server)
50
Max. % of memory used for
dynamic buffer cache
dbc_max_pct
55
Min. % of memory used for
dynamic buffer cache
dbc_min_pct
1 (enable)0
Enable/disable storing link
text for symlinks in disk
inode – HFS only
create_fastlinks
0 (dynamic)0
Number of 4K memory
pages in static buffer cache
bufpages
bufcache_hash_locks
Sizes the pool of locks used to control access to buffer cache data structures.
bufpages
The bufpages variable specifies how many 4096-byte memory pages are allocated for the static
sized buffer cache. Both bufpages and nbuf must be set to 0 to enable dynamic buffer cache.
create_fastlinks
When create_fastlinks is enabled, it causes the system to create HFS symbolic links in a manner
that reduces the number of disk accesses by one for each symbolic link in a pathname lookup.
dbc_min_pct
The value of dbc_min_pct specifies the minimum percentage of physical memory that is reserved
for use by the dynamic buffer cache.
dbc_max_pct
The value of dbc_max_pct specifies the maximum percentage of physical memory that is
reserved for use by the dynamic buffer cache.
default_disk_ir
When enabled, disk drives that have data caches return from a write() system call when the
data is cached, rather than returning after the data is written on the media. Data loss can occur
if the disk’s power fails, however this is usually negated via RAID strategies or arrays with UPS.