Useful Shell Commands

Manage Files and Folders

Copy all files in subfolders to the current folder. (Used when changed the filestorage rule in UCM)

find . -type f  -exec mv -t . {} +

Find Size of subfolders

du -sh *

Find a String in all files
sed -i 's/\/u01\/Oracle\/Middleware\/user_projects\/domains/\/mnt/g' *.hda

Recursively
find . -name *.hda -exec sed -i 's/\/u01\/Oracle\/Middleware\/user_projects\/domains/\/mnt/g' {} +

Manage Partitions and Disk

List the available Disk

fdisk -l

List the mounted disk and space available

df -k

Mount disk

mount /dev/sdf /ebs

Format Disk

mkfs.ext3 /dev/sdf

Resize partition to the full available disk

resize2fs /dev/xvda1

Keep Mounts after restart
Edit /etc/fstab and add

/dev/xvdi /media/newdrive/ ext3 defaults,noatime 0 0
/dev/xvdj  /u01      ext3   defaults,noatime        0 0

Firewall

Enable VNC connections (port 5901)

/etc/init.d/iptables -I INPUT 1 -p tcp --dport 5901 -j ACCEPT
/etc/init.d/iptables save

Disable iptables

/etc/init.d/iptables save
/etc/init.d/iptables stop
chkconfig iptables off

For RHEL
service firewalld stop
systemctl disable firewalld

Swap Space

Check Swap Space

swapon -s

Add Swap Space

1. Create a new swap file
   
   dd if=/dev/zero of=/myswapfile1 bs=1M count=1024
2. Change permission to only root
   
   chmod 600 /myswapfile1
3. setup file as swap
   
   mkswap /myswapfile1
4. Enable new swap space
   
   swapon /myswapfile1
5. to keep after reboot, add the following to /ect/fstap
   
   /myswapfile1 swap swap defaults 0 0

Network

Check If IPv6 is loaded

lsmod | grep ipv6

Change Hostname

hostname newname.domain

Change Hostname after reboot:
Edit /etc/sysconfig/network and add the followin

HOSTNAME=newname.domain

Check If IPv6 is loaded

lsmod | grep ipv6

Disable IPv6

1. 
   Edit/create the /etc/modprobe.d/modprobe.conf file and add the following:
   
   options ipv6 disable=1
   alias net-pf-10 off
   alias ipv6 off
   install ipv6 /bin/true
2. Edit /etc/sysconfig/network and add
   
   NETWORKING_IPV6=no
   IPV6INIT=no
3. Edit /etc/sysconfig/network-scripts/ifcfg-eth0 and add
   
   IPV6INIT=no
   IPV6_AUTOCONF=no