i'm wondering if there is a way to determine minimum memory requirement for AIX kernel and OS functions? We use memdetails script from perfpmr package to see actual memory allocation, for example like this:
You can see there is still some free memory but also that AIX kernel uses 13 GB on a 64 GB system. How can i tell what will be the maximum kernel memory? We measured this after reboot and starting the applications, kernel took only 2 GB but during 4 months it gradually grew to 13 GB. What would happen if i configured applications to take let's say 60 GB of memory. Will AIX handle that and live with 4 GB for kernel or will it start trashing until reboot is necessary? I can't seem to find any minimum OS requirements so i don't really know how much memory is available to applications. There are no exact figures, everyone only mentions it depends on running services, devices, network etc. etc. but there is no hint of how to calculate the maximum potential usage alltogether.
Anyone has dealt with this before that could help? I have been trying to apply for AIX Performance tuning training for last 3 years so i could ask these questions but since i was always the only one who applied, the course was never opened
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 NETBSD
viomb
VIOMB(4) BSD Kernel Interfaces Manual VIOMB(4)NAME
viomb -- VirtIO memory ballooning driver
SYNOPSIS
virtio* at pci? dev ? function ?
viomb* at virtio?
DESCRIPTION virtio(4) defines an interface for efficient, standard, and extensible I/O between the hypervisor and the virtual machine. The viomb driver
supports the virtio-compliant memory ballooning device.
Memory ballooning works as follows:
1. The host operator requests a guest to return some amount of memory to the host (via e.g. Qemu monitor balloon command).
2. The hypervisor sends the request via VirtIO memory ballooning device.
3. The guest viomb driver requests allocation of that amount of physical memory from the NetBSD memory management system.
4. The viomb device tells the hypervisor the guest physical memory address of the allocated memory via VirtIO memory ballooning device.
The sysctl node hw.viomb.npages shows the requested number of memory pages to return to the hypervisor, while hw.viomb.actual shows the
actual number of memory pages that are already returned to the hypervisor.
SEE ALSO virtio(4), sysctl(8)
Rusty Russell, IBM Corporation, Virtio PCI Card Specification, http://ozlabs.org/~rusty/virtio-spec/.
HISTORY
The viomb device driver appeared in NetBSD 6.0.
BUGS
The userland interface should be same as the Xen ballooning device.
BSD November 26, 2011 BSD