Linux Operating System that powered by Linux kernel have an advanced disk cache algorithm that used to store frequently access data from Hard disk.
This is to explain why some Linux server’s RAM still getting high memory usage even you upgrade your RAM.
To find out how much memory using by the Linux-based server, you may use the linux command “free” to track it. To get the detailed/actual memory usage, you may run the following command from your Linux box.
You should get some result as below,
total used free shared buffers cached
Mem: 15905 2879 13026 0 384 900
-/+ buffers/cache: 1593 14311
Swap: 3999 0 3999
With the result above, you may see that the used memory is 2879MB and free memory is 13026MB. However, the cached memory is 1593MB while the actual free memory will be 14311MB.
PlayOnLinux is a piece of software which allows you to easily install on your Linux box and it will just like running on Microsoft Windows.
It come with numerous games and apps that could just run with cost-free from your Linux box.
Now, you can visit them by http://www.playonlinux.com/
Database is the most important file other than web file, hence the backup is very important for the web developer and web owner.
By referring to the current post, you may backup your database automatically from your Linux box.
# Specify the temporary backup directory
# Database Name
# store the current date
# Specify Ftp details
# Dump the mysql database with the current date and compress it.
/usr/bin/mysqldump -u$dbuser -p$dbpasswd $dbname | gzip > $BKUPDIR/$date.$dbname.sql.gz
# Change directory to the backup directory
# Upload the backup
ftp -n $ftpserver <<!EOF!
user $ftpuser $ftppass
# Remove the local backup file
/bin/rm -f /$BKUPDIR/$date.$dbname.sql.gz
With the above script, you may save it as file.sh and just schedule a cronjob to run it as your needed time.
As you know Mick Genie ever post on how to set RSA key from Linux PC with URL below.
Create RSA key login for remote login
At the same time, I am being requested by @thebosscat as well for the step.
1. download the puTTYgen from URL below.
2. Run it.
3. Generate the key by mouse over from the red box as above.
4. Set the “Key passphrase” which same like password and copy the public key to your Linux box with file /root/.ssh/authorized_keys.
5. Click on the “Save private key” and save it with .ppk format.
6. Try to load ppk file with your pageant with your password and try to login without need a password.
If you still remember Mick Genie ever post on how to monitor RAM/Memory on Linux earlier from http://www.mickgenie.com/monitor-rammemory-on-linux/, you should have an idea on the basic command to monitor Linux server.
Today I would like to share some useful monitoring tools from Linux box. With Linux monitoring tools, it uses to analysis and debugging the Linux box.
1. Top Process
– Top process is the most used by the Linux user as it come with many useful information such as it’s server load, memory, iostat, etc.
With top command, it do comes with some hotkey.
t – Displays summary information off and on.
m – Displays memory information off and on.
A – Sorts the display by top consumers of various system resources. Useful for quick identification of performance-hungry tasks on a system.
f – Enters an interactive configuration screen for top. Helpful for setting up top for a specific task.
o – Enables you to interactively select the ordering within top.
r – Issues renice command.
k – Issues kill command.
z – Turn on or off color/mono Continue reading Useful Linux Monitoring Tools
With Apache Linux box, sometimes you might get lots of file named core.xxxx where xxxx is some number. You might wonder what is these file.
Normally core.xxxx file was generated from Linux box and holds the current state of a process working memory when a process is crashed. To read the file, run the command as below from your shell.
From the strings reading, each line represent different state of a process.
Sometimes, you might required to compress or extract .rar file from Linux box which do not come by default, however you may install it manually.
Under Debian Linux, you need to type apt-get as follows to install unrar program:
apt-get install unrar
Under Fedora core Linux then use yum command
yum install unrar
If the above method not working, you may copy the following command and paste to your console line.
cd /tmp;wget http://www.rarlab.com/rar/rarlinux-3.6.0.tar.gz;tar zxf rarlinux-3.6.0.tar.gz;cd rar;cp rar unrar /bin