Posts Tagged ‘loader’

Fix “Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.” in FreeBSD

Monday, May 21st, 2012

bsdinstall-newboot-loader-menu-pv_entries_consider_increasing_vm_pmap_shpgrepproc

I'm running FreeBSD with Apache and PHP on it and I got in dmesg (kernel log), following error:

freebsd# dmesg|grep -i vm.pmap.shpgperproc
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.

The exact FreeBSD, Apache and php versions I have installed are:
 

freebsd# uname -a ; httpd -V ; php –version
FreeBSD pcfreak 7.2-RELEASE-p4 FreeBSD 7.2-RELEASE-p4 #0: Fri Oct 2 12:21:39 UTC 2009 root@i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
Server version: Apache/2.0.64
Server built: Mar 13 2011 23:36:25Server's Module Magic Number: 20050127:14
Server loaded: APR 0.9.19, APR-UTIL 0.9.19
Compiled using: APR 0.9.19, APR-UTIL 0.9.19
Architecture: 32-bit
Server compiled with….
-D APACHE_MPM_DIR="server/mpm/prefork"
-D APR_HAS_SENDFILE
-D APR_HAS_MMAP
-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
-D APR_USE_FLOCK_SERIALIZE
-D APR_USE_PTHREAD_SERIALIZE
-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
-D APR_HAS_OTHER_CHILD
-D AP_HAVE_RELIABLE_PIPED_LOGS
-D HTTPD_ROOT="/usr/local"
-D SUEXEC_BIN="/usr/local/bin/suexec"
-D DEFAULT_PIDLOG="/var/run/httpd.pid"
-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
-D DEFAULT_LOCKFILE="/var/run/accept.lock"
-D DEFAULT_ERRORLOG="logs/error_log"
-D AP_TYPES_CONFIG_FILE="etc/apache2/mime.types"
-D SERVER_CONFIG_FILE="etc/apache2/httpd.conf"
PHP 5.3.5 with Suhosin-Patch (cli) (built: Mar 14 2011 00:29:17)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with eAccelerator v0.9.6.1, Copyright (c) 2004-2010 eAccelerator, by eAccelerator

After a bunch of research a FreeBSD forums thread , I've found the fix suggested by a guy.

The solution suggested in the forum is to raise up vm.pmap.pv_entry_ma to vm.pmap.pv_entry_max=1743504, however I've noticed this value is read only and cannot be changed on the BSD running kernel;

freebsd# sysctl vm.pmap.pv_entry_max=1743504
sysctl: oid 'vm.pmap.pv_entry_max' is read only

Instead to solve the;

Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
, I had to add in /boot/loader.conf

vm.pmap.pde.mappings=68
vm.pmap.shpgperproc=500
vm.pmap.pv_entry_max=1743504

Adding this values through /boot/loader.conf set them on kernel boot time. I've seen also in the threads the consider increasing either the vm.pmap.shpgperproc is also encountered on FreeBSD hosts running Squid, Dansguardion and other web proxy softwares on busy hosts.

This problems are not likely to happen for people who are running latest FreeBSD releases (>8.3, 9.x), I've read in same above post in newer BSD kernels the vm.pmap is no longer existing in newer kernels.

How to disable ACPI (power saving) support in FreeBSD / Disable acpi on BSD kernel boot time

Tuesday, May 15th, 2012

FreeBSD disable ACPI how ACPI Basic works basic diagram

On FreeBSD the default kernel is compiled to support ACPI. Most of the modern PCs has already embedded support for ACPI power saving instructions.
Therefore a default installed FreeBSD is trying to take advantage of this at cases and is trying to save energy.
This is not too useful on servers, because saving energy could have at times a bad impact on server performance if the server is heavy loaded at times and not so loaded at other times of the day.

Besides that on servers saving energy shouldn't be the main motivator but server stability and productivity is. Therefore in my personal view on FreeBSD used on servers it is better to disable complete the ACPI in order to disable CPU fan control to change rotation speeds all the time from low to high rotation cycles and vice versa at times of low / high server load.

Another benefit of removing the ACPI support on a server is this would probably increase the CPU fan life span and possibly prevent the CPU to be severely heated at times.

Moreover, some piece of hardware might have troubles in properly supporting ACPI specifications and thus ACPI could be a reason for unexpected machine hang ups.

With all said I would recommend to anyone willing to use BSD for a server to disable the ACPI (Advanced Configuration and Power Interface), just like I did.

Here is how;

1. Quick review on how ACPI is handled on FreeBSD

acpi support is being handled on FreeBSD by a number of loadable kernel modules, here is a complete list of all the kernel modules dealins with acpi:

freebsd# cd /boot
freebsd# find . -iname '*acpi*.ko'
./kernel/acpi.ko
./kernel/acpi_aiboost.ko
./kernel/acpi_asus.ko
./kernel/acpi_fujitsu.ko
./kernel/acpi_ibm.ko
./kernel/acpi_panasonic.ko
./kernel/acpi_sony.ko
./kernel/acpi_toshiba.ko
./kernel/acpi_video.ko
./kernel/acpi_dock.ko

By default on FreeBSD, if hardware has some support for ACPI the acpi gets activated by acpi.ko kernel module. The specific type of vendors specific ACPI like IBM, ASUS, Fujitsu are controlled by the respective kernel module from the list …

Hence, to control if ACPI is loaded or not on a FreeBSD system with no need to reboot one can use kldload, kldunload module management BSD cmds.

a) Check if acpi is loaded on a BSD

freebsd# kldstatkldstat | grep -i acpi
9 1 0xc9260000 57000 acpi.ko

b) unload kernel enabled ACPI support

freebsd# kldunload acpi

c) Load acpi support (not the case with me but someone might need it, if for instance BSD is running on laptop)

freebsd# kldload acpi

2. Disabling ACPI to load on bootup on BSD

a) In /boot/loader.conf add the following variables:

hint.acpi.0.disabled="1"
hint.p4tcc.0.disabled=1
hint.acpi_throttle.0.disabled=1


b) in /boot/device.hints add:

hint.acpi.0.disabled="1"

c) in /boot/defaults/loader.conf make sure:

##############################################################
### ACPI settings ##########################################
##############################################################
acpi_dsdt_load="NO" # DSDT Overriding
acpi_dsdt_type="acpi_dsdt" # Don't change this
acpi_dsdt_name="/boot/acpi_dsdt.aml"
# Override DSDT in BIOS by this file
acpi_video_load="NO" # Load the ACPI video extension driver

d) disable ACPI thermal monitoring

It is generally a good idea to disable the ACPI thermal monitoring, as many machines hardware does not support it.

To do so in /boot/loader.conf add

debug.acpi.disabled="thermal"

If you want to learn more on on how ACPI is being handled on BDSs check out:

freebsd# man acpi

Other alternative method to permanently wipe out ACPI support is by not compiling ACPI support in the kernel.
If that's the case in /usr/obj/usr/src/sys/GENERIC make sure device acpi is commented, e.g.:

##device acpi

 

WP-Minify, Scripts Gzip and HeadJS Loader three scripts that might have positive impact on WordPress performance

Friday, September 23rd, 2011

I’m trying to get the most of server + wordpress performance and these days I’m heavily playing with it as one can read from my past few articles 😉

Today I’ve come across three other plugins which in many cases could be beneficial and bring a good performance increase in wordpress, this are:
 

  • WP-Minify – http://wordpress.org/extend/plugins/wp-minify/
  • HeadJS Loader – http://wordpress.org/extend/plugins/headjs-loader/
  • Scripts Gzip – http://wordpress.org/extend/plugins/scripts-gzip/

WP-Minify – does combine all JS and CSS script into one consolidated compressed script or style as well removes any duplicate script resources and hence could have positive impact on performance

HeadJS Loader – does strips out all your old javascript declarations and puts them into one head.js file so that they are loaded in parallel in the head of the pages and through that prevents the blocking of load up until all JS is a loaded so commonly seen these days on the net for more info on how HeadJS works check out http://headjs.com

Script Gzip – merges and compresses the CSS and JS links on page, the plugin does not have caching functionality. The plugin doesn’t have much configuration options which I find as a good thing

To find out what works best for you its a best practice if the website speed load time is tested after loading each of the plugins and with all of them enabled and configured, finally for best results just leave only the plugins or a combination of them which gives the lowest page responce times.

How to fix php “Fatal error: Class ‘SimpleXMLElement’ not found” and “Fatal error: Class ‘JLoader’ not found” on FreeBSD

Tuesday, June 21st, 2011

One of the contact forms running on a FreeBSD server configured to work on top of Apache+MySQL suddenly stopped working.

The errors that appeared on the webpage during a page request to the form url was:

Fatal error: Class 'SimpleXMLElement' not found in /var/www/joomla/plugins/system/plugin_googlemap2_helper.php on line 2176 Fatal error: Class 'JLoader' not found in /var/www/joomla/plugins/libraries/loader.php on line 161

As you see in the output the website which was causing the issues was running a Joomla version 1.5.23 Stable configured with RSForm!ver 1.5.x (as a contact form solution) and Google Maps version 2.13b plugins.

The Google Map from Google Maps plugin and the RSform were configured to appear on one physical configured article in Joomla and seemed to work just until now. However yesterday suddenly the error messages:
Fatal error: Class ‘SimpleXMLElement’ not found
Fatal error: Class ‘JLoader’ not found

came out of nothing, it’s really strange as I don’t remember doing any changes to either Joomla or the PHP installation on this server.
There is one more guy who has access to the Joomla installation which I suspect might have changed something in the Joomla, but this scenario is not very likely.

Anyways as the problem was there I had to fix it up. Obviously as the error message Fatal error: Class ‘SimpleXMLElement’ not found reported the server php simplexml was missing!

Just to assure myself the php simplexml extension is not present on the server I used the classical method of setting up a php file with phpinfo(); in it to check all the installed php extensions on the server.

Finally to solve the issue I had to install the module from ports php5-simplexml , e.g.:

freebsd# cd /usr/ports/textproc/php5-simplexml
freebsd# make install clean

Afterwards to make the new settings take place I did restart of my Apache server:

freebsd# /usr/local/etc/rc.d/apache2 restart
Syntax OK
Stopping apache2.
Waiting for PIDS: 63883.
Performing sanity check on apache2 configuration:
Syntax OK
Starting apache2.

Now my Joomla contact form is back to normal 😉

If someone has any idea why this error occured without any php or server modifications, and how comes that all worked fine beforehand even though I did not have the simplexml module instlaled on the server o_O, I would be enormously greatful.

How to install GNOME server on Ubuntu 10.04.2 LTS Lucid

Wednesday, April 20th, 2011

After some upgrades of Ubuntu from 9.10 to Ubuntu 10.04.2, I faced problems during apt-get upgrade && apt-get dist-upgrade

I had to fix it up with apt-get upgrade -f , however the “fix” which was targetting a fix up to the apt-get dist-upgrade removed about 260 packages, among which were the grub boot loader , xorg-server and even gnome

As in order to fix the package mishap the apt-get update -f was my only possible solution I went by and confirmed that I would like to wipe out all the packages.

Logically afterwards it was required that I install my missing xorg-server and gnome in order to make the Ubuntu desktop work again.

Here is how:

ubuntu:~# apt-get update && apt-get xorg-server ubuntu-desktop

The ubuntu-desktop is a meta package which installs the GNOME environment.