Recursively check ownership of all files

find files in a folder and their user permission other than oracle

find <<Starting search location>> -not -user oracle -printf "%p %u\n"

find files in a folder and thier group permission other than oinstall

find <<Starting search location>>  -not -user oinstall -printf "%p %u\n" 

Change Display Resolution of Oracle Linux 6.5

Check the all possible resolution supported using the following command:
# xrandr

Change or set the resolution using the available resolution

#xrandr -s 1024x768

Linux: Delete Files Older than x number of days

Delete files older than x number of days

$find . -mtime +5 -print 0 |xargs -0 rm -f

How To Install LVMs With a GUI

The Logical Volume Manager or LVM

Install LVM GUI utility

On RHEL

You can install the package using the CLI, by issuing in a terminal:

#yum install system-config-lvm

Once installed, you can issue the following command to launch it:

#sudo system-config-lvm

Once installed  the program will appear under “System” -> “Administration” -> “Logical Volume Management”.

Removing Special Character File Names in Linux

Accidentally a file was created with a name of "-rw-r--r--.err". I can't remove this file using our normal shell commands. At last lot of searches in Google I found a solution.

Find the inode of the file using the following command

$ ls –il

 9078727 is inode number.

Now Use find command to delete file by inode:

$ find . -inum 9078727 -exec rm -f {} \;

It will find that file and will remove it with force i.e remove without prompt.

Linux Network bonding

Linux Network bonding

Linux network Bonding is creation of a single bonded interface by combining 2 or more Ethernet interfaces. This helps in high availability of your network interface and offers performance improvement. Bonding is same as port trunking or teaming.

Steps for bonding in Redhat Enterprise Linux are as follows.. 


Step 1.

Create the file ifcfg-bond0 with the IP address, netmask and gateway. Shown below is my test bonding config file.

$ cat /etc/sysconfig/network-scripts/ifcfg-bond0

DEVICE=bond0
IPADDR=10.183.90.86
GATEWAY=10.183.90.1
NETMASK=255.255.255.0
NETWROK=10.183.90.0
USERCTL=no
BOOTPROTO=none
ONBOOT=yes




Step 2.

Modify eth0 and eth1  configuration as shown below. Comment out, or remove the ip address, netmask, gateway and hardware address from each one of these files, since settings should only come from the ifcfg-bond0 file above. Make sure you add the MASTER and SLAVE configuration in these files.

$ cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
BOOTPROTO=none
HWADDR=00:1C:C4:96:21:60
ONBOOT=yes
# setting for Bond
MASTER=bond0
SLAVE=yes


$ cat /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1
BOOTPROTO=none
HWADDR=00:1C:C4:96:21:62
ONBOOT=yes
MASTER=bond0
SLAVE=yes

Step 3.

Set the parameters for bond0 bonding kernel module. Select the network bonding mode based on you need, documented at http://unixfoo.blogspot.com/2008/02/network-bonding-part-ii-modes-of.html. The modes are

·       mode=0 (Balance Round Robin)

·       mode=1 (Active backup)

·       mode=2 (Balance XOR)

·       mode=3 (Broadcast)

·       mode=4 (802.3ad)

·       mode=5 (Balance TLB)

·       mode=6 (Balance ALB)

Add the following lines to /etc/modprobe.conf

# bonding commands
alias bond0 bonding
options bond0 mode=1 miimon=100 


Step 4.

Load the bond driver module from the command prompt.

$ modprobe bonding


Step 5.

Restart the network, or restart the computer.

$ service network restart # Or restart computer

When the machine boots up check the proc settings.

$ cat /proc/net/bonding/bond0 

Look at ifconfig -a and check that your bond0 interface is active. 

To verify whether the failover bonding works.. 

•   Do an ifdown eth0 and check /proc/net/bonding/bond0 and check the “Current Active slave”. 
•    Do a continuous ping to the bond0 ipaddress from a different machine and do a ifdown the active interface. The ping should not break.

 

Number of files in a folder

Number of files in a folder

find . -type  f| wc -l

Number of Subfolders in a folder
find . -type d | wc -l

Number of folders in current folder then

find . -maxdepth 1 -type d | wc -l

Rename a linux mount point

Unmount the existing mount point (that you want to rename) :
#umount /prodapp




Change the label on the filesystem to the new mount point name:
#tune2fs -L /u01 /dev/sdb2

add the entries to /etc/fstab:
replace the entries of /prodapp with new mount point

Create the mount point named /u01
mkdir /u01

mount the new folder /u01:
mount  /u01

remove the folder /prodapp:
rmdir -rf /prodapp

Update etc_fstab file while linux started with repair mode

Use following command to mount the filesystem with writable permission:

Repair filesystem # mount -w -o remount /

After this you can go and change /etc/fstab file. Restart your computer and that’s it.

Mount Remote Windows Folder with RHEL 5 Linux

Login into linux using root user

Create the required mount point in linux
#mkdir -p /mnt/win_folder   
mount the remote folder
#mount -t cifs //windows_machine_ip_or_name//shared_folder -o username=test,password=test123 /mnt/win_folder

-t cifs - file system type to be mount
-o : are options passed to mount command, here i have passed 2 options username and password
//windows_machine_ip_or_name//shared_folder - windows/shared folder
 /mnt/win_folder - linux mount point

Configure the system to automount while starting

add entry into /etc/fstab
Open file /etc/fstab using vi text editor:# vi /etc/fstabAppend line
//windows_machine_ip_or_name//shared_folder /mnt/win_folder cifs username=test,password=test123 0 0