Description of Tunable Parameters for HPUX 11.0 DocId: KBRC00002354 Updated: 5/5/03 11:44:00 AM
PROBLEM
Can you provide information on the following Kernel Parameters?
vx_ninode
vx_noifree
CONFIGURATION
HPUX 11.0
RESOLUTION
Patch PHKL_17953 adds VxFS tunables:
VX_NINODE
VX_NOIFREE
VX_NINODE allows setting the maximum number of inodes
that can be present in the VxFS in-memory inode cache.
If set to zero (the default) the size is tuned
according to how much physical memory the system
has. Decreasing the maximum size of the inode cache
reduces the fragmentation it causes.
To see what size the inode cache is on a running system:
# echo 'vxfs_ninode/D' | adb /stand/vmunix /dev/mem
So that this system will have a maximum of 8000 inodes
allocated in the VxFS cache.
VX_NOIFREE controls whether to free memory from the VxFS inode cache.
If set to zero (the default), inodes are eventually freed
back to the general memory pool if they are unused. If VX_NOIFREE
is non-zero, then memory is never freed from the
VxFS inode cache. It may seem counter-intuitive
to hoard memory to prevent memory problems, but
not freeing the 2KB buckets holding VxFS inodes to
the general memory pool prevents fragmentation of
the pool. Once the maximum size is reached for
the inode cache, VxFS will always re-use older inodes.
How to find the total used and free inodes on the system DocId: UPERFKBRC00009350 Updated: 3/22/02 5:43:00 PM
PROBLEM
How do I find the total number of inodes used on the system? bdf -i shows this
per filesystem but does not add up the total and the sar -v output for inode
cache does not show the number of JFS inodes used. CONFIGURATION
HP-UX 11.0RESOLUTION
First, some important notes here about inodes taken from DocId:
UPERFKBAN00000726 "Introduction to performance tuning for HP-UX":
Inode count as expressed by sar, only refers to the cache size for HFS inodes
not the actual inode count.
The kernel parameter ninode only effects HFS filesystems, JFS (VxFS) allocate
their own inodes dynamically (vx_ninode) based on the amount of available
memory. The number of inodes for a vxfs file systems is unlimited by default.
A JFS inode takes up 256 bytes.
To determine the amount of vxfs inodes allocated (these are not reported by
sar) run :
example:
echo vxfs_ninode/D | adb -k /stand/vmunix /dev/mem
vxfs_ninode:
vxfs_ninode: 64000
The following script simply takes the output of bdf -i and totals the numbers
for all the local filesystems (JFS and HFS). The output of the script looks
something like this:
Total fs space is 111026581
Total used space is 57482142
Total free space is 52289315
Total used inodes is 134232
Total free inodes is 5033952
The following script was written by Mike Saavedra at Hewlett Packard.
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#!/usr/bin/sh
integer t u f iu if
#integer f
t=0
a=0
u=0
iu=0
if=0
bdf -i | grep "^/dev" | while read line
do
set $line
#echo "$2 $3 $4 $6 $7"
(( t = t + $2 ))
(( u = u + $3 ))
(( f = f + $4 ))
(( iu = iu + $6 ))
(( if = if + $7 ))
done
echo "\nTotal fs space is $t \n"
echo "Total used space is $u \n"
echo "Total free space is $f \n"
echo "Total used inodes is $iu \n"
echo "Total free inodes is $if \n"
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