2009/01/06

Network Time (NTP) service in CentOS

Synchronize the clocks is standard now-da-day. If you don't have NTP for some reason, here's how you set it up in CentOS.

First Install the NTP Package on your server as root.

# yum install ntp
Loading “fastestmirror” plugin
Loading mirror speeds from cached hostfile
* base: mirror.steadfast.net
* updates: mirrors.liquidweb.com
* addons: pubmirrors.reflected.net
* extras: pubmirrors.reflected.net
Setting up Install Process
Parsing package install arguments
Resolving Dependencies
–> Running transaction check
—> Package ntp.i386 0:4.2.2p1-8.el5.centos.1 set to be updated
–> Finished Dependency Resolution

Dependencies Resolved

=================================================================
Package Arch Version Repository Size
=================================================================
Installing:
ntp i386 4.2.2p1-8.el5.centos.1 base 1.3 M

Transaction Summary
=================================================================
Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)

Total download size: 1.3 M
Is this ok [y/N]: y
Downloading Packages:
(1/1): ntp-4.2.2p1-8.el5. 100% |=========================| 1.3 MB 00:19
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing: ntp ######################### [1/1]

Installed: ntp.i386 0:4.2.2p1-8.el5.centos.1
Complete!

Next set it to start automatically on a reboot

# chkconfig ntpd on

Tell it which NTP server it should update it’s time from

# ntpdate pool.ntp.org
4 Aug 12:32:43 ntpdate[9540]: step time server 64.202.112.75 offset 1256.453048 sec

Verify that the Time & Date are correct

# date
Mon Aug 4 12:33:04 EDT 2008

Finally start the service

# service ntpd start
Starting ntpd: [ OK ]

2008/12/22

Windows UI - change to mac style

hide the windows bar and replace with this.



Get it free at http://rocketdock.com/

Beryl - change what u think about Linux UI

Beryl is an OpenGL accelerated desktop that seeks to provide a free, open source desktop experience to the community that reflects the wishes of the users. Above all else, the project seeks to listen to and respond to the requests of the user base...


Windows Vista (Aero) Vs Linux Ubuntu (Beryl) - The funniest videos are a click away

Installing Beryl On A CentOS 5.0 Desktop: http://www.howtoforge.com/beryl_centos5.0

Mount new disk on CentOS

1. Check what is the new hard disk device name with "fdisk -l", it should be something like /dev/sda. You can easily identify which is the new drive by running "mount" and finding the drive that exists in "fdisk -l" but is not mounted.
mount; fdisk -l

2. Create a partition on the new drive, (the sample code below assume the disk is /dev/sdd)
fdisk /dev/sdd

3. Create a filesystem on the new partition, we use ext3 file system.
mkfs.ext3 /dev/sdd

4. Create a directory named whatever you like, this will be where you mount the new disk
mkdir /backup

5. Edit /etc/fstab an add a record for the new drive at the end of the file. This will make the server mount the drive automatically after reboot. Mount options (like noatime and nodiratime) can be added as a comma separated list of values after "defaults": "defaults,noatime,nodiratime"

echo "/dev/sdd /backup ext3 defaults 0 0" >> /etc/fstab

Linux records information about when files were created and last modified as well as when it was last accessed. There is a cost associated with recording the last access time. Linux has a special mount option for file systems called noatime that can be added to each line that addresses one file system in the /etc/fstab file. If a file system has been mounted with this option, reading accesses to the file system will no longer result in an update to the atime information associated with the file. The importance of the noatime setting is that it eliminates the need by the system to make writes to the file system for files which are simply being read. Since writes can be somewhat expensive, this can result in measurable performance gains.

nodiratime does the same thing but for directories. I know the beginners guide says to use both mount options on file systems, but from others I've talked to and places I've read it seems noatime implies nodiratime because noatime is a superset and nodiratime is a subset used specifically to disable it for directories but leave it on for files, and when you use noatime, it does it for everything, files/dirs

echo "/dev/sdd /backup ext3 rw,noatime,nodiratime 0 0" >> /etc/fstab

Mount the drive. "mount -a" just mounts everything according to /etc/fstab.

mount -a

Reboot to make sure it starts ok with the new drive mounted.

2008/12/20

MonoDevelop 1.91 on Cent OS

Last post we installed Mono 2.x run time. Here we will get MonoDevelop install on GNOME, for development environment.

First, here are the related software. You should have most of them when installing the run-time:

yum install glib2-devel pango-devel gtk2-devel glade2-devel libgnome-devel \
gnome-desktop-devel gnome-panel-devel libgnomeprintui22-devel \
gtksourceview-devel ruby ruby-rdoc gtkhtml38-devel wget

Now, we need make the required environment variables while we're building the IDE, as well in its run-time. So let's make it into shellscript called env.sh (or whatever you like it).

echo 'PATH="/opt/mono/bin:$PATH"' /opt/mono/env.sh
echo 'export PKG_CONFIG_PATH=/opt/mono/lib/pkgconfig' >> /opt/mono/env.sh
echo 'export LD_LIBRARY_PATH=/opt/mono/lib' >> /opt/mono/env.sh
echo 'source /opt/mono/env.sh' >> /opt/mono/env.sh

chmod +x /opt/mono/env.sh

Now we are ready to build MonoDevelop from tarball source. The following packages are the minimum software needed - we will build them one-by-one:

gtk-sharp

cd ~/
wget http://ftp.novell.com/pub/mono/sources/gtk-sharp212/gtk-sharp-2.12.5.tar.bz2
tar xjf gtk-sharp-2.12.5.tar.bz2
cd ./gtk-sharp-2.12.5
./configure --prefix=/opt/mono
make;make install

Mono.Addins

wget http://ftp.novell.com/pub/mono/sources/mono-addins/mono-addins-0.3.1.tar.bz2
cd ./mono-addins-0.3.1
./configure --prefix=/opt/mono
make;make install

Monodoc

wget http://ftp.novell.com/pub/mono/sources/monodoc/monodoc-2.0.zip
unzip monodoc-2.0.zip
cd ./monodoc-2.0
./configure --prefix=/opt/mono
make;make install

Mono Tools

wget http://ftp.novell.com/pub/mono/sources/mono-tools/mono-tools-2.0.tar.bz2
tar jfxv mono-tools-2.0.tar.bz2
cd ./mono-tools-2.0
./configure --prefix=/opt/mono
make;make install

MonoDevelop

wget http://ftp.novell.com/pub/mono/sources/monodevelop/monodevelop-1.9.1.tar.bz2
tar jfxv monodevelop-1.9.1.tar.bz2
cd ./monodevelop-1.9.1
./configure --prefix=/opt/mono
make;make install

You should now able to start up MonoDevelop in GNOME, enjoy.

Mercury簡易改裝

有同好有一樣的困擾 - 如何使用自己的data logging軟體,因此寫了這篇來分享我的簡易改裝。 Background 雲豆子 MERCURY roaster 烘豆機的設計是使用自行開發的軟體,來:1. 操控風門/火力; 2. data logging/自動烘焙。 ...