vmstat -v shows that about 20% of memory pages are pinned (that would roughly correspond to those 13 GB for kernel). Does it mean that application doesn't use memory pinning (server is running Oracle+SAP)? svmon tells me that oracle and workprocesses use about 33 MB of pinned memory, perhaps it's the way they are designed. I'll have to check on some testing system what happens, if you continually increase memory for aplication, how it will affect OS behaviour.
Hello,
I'm using a unix server (HP rp2450) which has : 2 Go RAM memory and 4 Go swap.
Here is the result of vmstat -n command :
$ vmstat -n
VM
memory page faults
avm free re at pi po fr de sr in sy ... (5 Replies)
This is post number 3 in a series of unanswered "TUNING" questions. :D
With AIX 5.3 TL4, the page size can vary from the original "4k". They can now be "64k" and a couple other sizes. They also do not have to all be the same. Some can remain "4k" while others are "64k" which is what seems to... (2 Replies)
Hi
I am trying to investigate a disk performance issue, and we are not seem to be hitting the right direction in our analysis.
This is a FC disk running on USP1000 HDS system. The application is an IO intensive application, but our opinion is that it is not performing due to perceived disk... (1 Reply)
Dear friends. can anybody suggest me what to be considered in order to achieve maximum performance of AIX on which DB2 will be installed
Thanks is advance :) (1 Reply)
Dears i want to have a clear view about this tuning parameters and what they related to FS or Oracle , and how to figure the percentage of them .
maxperm%
maxclient%
v_pinshm = 1
lgpg_regions = 0
lpgp_size = 0 (3 Replies)
For some reason, my AIX 5.2 box has become slow in accepting telnet requests from others boxes. Windows, times out the connection, whereas, Unix it will wait for the AIX to display the login. I connect and it respawns back and says connected, but then sits and wait for what seems forever to get the... (5 Replies)
Hi,
we've a gigabit Ethernet adapter. And we wanted to improve the performance by tuning network parameters. so' as per IBM info center,
http://publib.boulder.ibm.com/infocenter/aix/v7r1/index.jsp?topic=%2Fcom.ibm.aix.prftungd%2Fdoc%2Fprftungd%2Fnetw_opt.htm
we tried changing the tuning... (2 Replies)
I have a IBM Power9 server coupled with a NVMe StorWize V7000 GEN3 storage, doing some benchmarks and noticing that single thread I/O (80% Read / 20% Write, common OLTP I/O profile) seems slow.
./xdisk -R0 -r80 -b 8k -M 1 -f /usr1/testing -t60 -OD -V
BS Proc AIO read% IO Flag IO/s ... (8 Replies)
Discussion started by: c3rb3rus
8 Replies
LEARN ABOUT FREEBSD
pae
PAE(4) BSD/i386 Kernel Interfaces Manual PAE(4)NAME
PAE -- Physical Address Extensions
SYNOPSIS
options PAE
DESCRIPTION
The PAE option provides support for the physical address extensions capability of the Intel Pentium Pro and above CPUs, and allows for up to
64 gigabytes of memory to be used in systems capable of supporting it. With the PAE option, memory above 4 gigabytes is simply added to the
general page pool. The system makes no distinction between memory above or below 4 gigabytes, and no specific facility is provided for a
process or the kernel to access more memory than they would otherwise be able to access, through a sliding window or otherwise.
SEE ALSO smp(4), tuning(7), config(8), bus_dma(9)HISTORY
The PAE option first appeared in FreeBSD 4.9 and FreeBSD 5.1.
AUTHORS
Jake Burkholder <jake@FreeBSD.org>
BUGS
Since KLD modules are not compiled with the same options headers that the kernel is compiled with, they must not be loaded into a kernel com-
piled with the PAE option.
Many devices or their device drivers are not capable of direct memory access to physical addresses above 4 gigabytes. In order to make use
of direct memory access IO in a system with more than 4 gigabytes of memory when the PAE option is used, these drivers must use a facility
for remapping or substituting physical memory which is not accessible to the device. One such facility is provided by the busdma interface.
Device drivers which do not account for such devices will not work reliably in a system with more than 4 gigabytes of memory when the PAE
option is used, and may cause data corruption. The PAE kernel configuration file includes the PAE option, and explicitly excludes all device
drivers which are known to not work or have not been tested in a system with the PAE option and more than 4 gigabytes of memory.
Many parameters which determine how memory is used in the kernel are based on the amount of physical memory. The formulas used to determine
the values of these parameters for specific memory configurations may not take into account the fact there may be more than 4 gigabytes of
memory, and may not scale well to these memory configurations. In particular, it may be necessary to increase the amount of virtual address
space available to the kernel, or to reduce the amount of a specific resource that is heavily used, in order to avoid running out of virtual
address space. The KVA_PAGES option may be used to increase the kernel virtual address space, and the kern.maxvnodes sysctl(8) may be used
to decrease the number of vnodes allowed, an example of a resource that the kernel is likely to overallocate in large memory configurations.
For optimal performance and stability it may be necessary to consult the tuning(7) manual page, and make adjustments to the parameters docu-
mented there.
BSD April 8, 2003 BSD