If you have 4 GB or more RAM use the Linux kernel compiled for PAE capable machines. Your machine may not show up total 4GB ram. All you have to do is install PAE kernel package.
This package includes a version of the Linux kernel with support for up to 64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).
The non-PAE kernel can only address up to 4GB of memory. Install the kernel-PAE package if your machine has more than 4GB of memory (>=4GB).
# yum install kernel-PAE
If you want to know how much memory centos is using type this in a terminal:
# cat /proc/meminfo
Many motherboards nowadays have integrated gigabit ethernet that use the Realtek NIC chipset.
The Realtek r8168B network card does not work out of the box in Redhat/Centos 5.3: instead of loading the r8168 driver, modprobe loads the r8169 driver, which is broken as can be seen with ifconfig which shows large amounts of dropped packets. A solution is to download the r8168 driver from the Realtek website and install it using the following steps:
Check whether the built-in driver, r8169.ko (or r8169.o for kernel 2.4.x), is installed.
# lsmod | grep r8169
If it is installed remove it.
# rmmod r8169
Download the R8168B linux driver from here into /root.
Unpack the tarball :
# cd /root
# tar vjxf r8168-8.012.00.tar.bz2
Change to the directory:
# cd r8168-8.012.00
If you are running the target kernel, then you should be able to do :
# make clean modules
# make install
# depmod -a
# insmod ./src/r8168.ko (or r8168.o in linux kernel 2.4.x)
make sure modprobe knows not to use r8169, and that depmod doesn’t find the r8169 module.
# echo "blacklist r8169" >> /etc/modprobe.d/blacklist
# mv /lib/modules/`uname -r`/kernel/drivers/net/r8169.ko \ /lib/modules/`uname -r`/kernel/drivers/net/r8169.ko.bak
You can check whether the driver is loaded by using the following commands.
# lsmod | grep r8168
# ifconfig -a
If there is a device name, ethX, shown on the monitor, the linux driver is loaded. Then, you can use the following command to activate it.
# ifconfig ethX up
After this you should not see any more dropped packets reported.
In this article Yvonne Milne looks at the use of the Recital Remote Data Connectivity Functions with Recital Database Gateways.
The Compatibility Dialog settings are written to the compat.db file in <path>/conf - please ensure that the user setting the compatibility settings has write access to this file and directory. Once these settings are written, the dialog will not be displayed unless SET COMPATIBLE is issued.
On exit of an .rsp page.
SAVE DATASESSION TO m_state
_SESSION["state"] = m_state
On entry to an .rsp page.
IF type( _session["state"] ) != "U"
m_state = _session["state"]
RESTORE DATASESSION FROM m_state
ENDIF
auth sufficient pam_krb5.so try_first_pass
auth sufficient pam_unix.so shadow nullok try_first_pass
account required pam_unix.so broken_shadow
account [default=bad success=ok user_unknown=ignore] pam_krb5.so
When stress testing our loadbalancer, i was unable to get more than 20 reliable ssh connections. The following error would be reported.
ssh_exchange_identification: Connection closed by remote host
The resolution for this is quite simple.
Edit the /etc/ssh/sshd_config file and increase the MaxStartups. On my server i set this to 200.
Edit /etc/sysctrl.conf and add the following line:
net.core.netdev_max_backlog = 3000
Then apply this change:
# sysctl -p
In Adobe's own words:"Adobe® AIR® is a cross-operating system runtime that lets developers combine HTML, Ajax, Adobe Flash®, and Adobe Flex® technologies to deploy rich Internet applications (RIAs) on the desktop."
The outcome of this combination of technologies is that developers can design and render quite beautiful user interfaces cross platform. For us desktop Linux users it is nice to have
an additional avenue for obtaining and running attractive desktop applications.Examples of great Adobe air applications are Adobe.com for My Desktop, TweetDeck and the Times Reader. You can download these applications and many more at the Adobe Marketplace.
The easiest way to install Adobe Air on Fedora 12 is to download the latest build from Adobe, click here.
Once you have downloaded the .bin file do the following at the shell:
su - chmod +x AdobeAIRInstaller.bin ./AdobeAIRInstaller.binOnce you have Air installed, there is a slight tweak you will have to do to get it running on Fedora 12, it is related to the security certificates. This can be remedied in one simple line at the shell prompt as root.
su - for c in /etc/opt/Adobe/certificates/crypt/*.0; do aucm -n $(basename $c) -t true; doneWhat this line is doing is using the aucm which is the Adobe Unix certificate manager to set the certificates installed as trusted.
You will now be able to go to the Adobe Marketplace and download and run Air applications without any issues.
Enjoy!