Changing Mount Point In Linux / Unix
Linux / Unix machine changing mounting point is crucial. While changing the mount points you need to be very careful or else data lose might occurs.
Suppose consider a situation like this, you have a partition for your SQL Database and the partition is mounted in /Database with size of 1024 MB and almost 730 MB is been utilized so you are planning to increase the size of the partition. In the mean while their is an another partition called /linux with size 2048 MB with only 30+ MB is been utilized.
Then to increase the size of the /Database partition we going to swap the /Database partition to /linux partition. The main thing you need to concentrate here is you need to do this with out data lose. Then why waiting lets go!!!
Step 1: First verify the size of the both partitions and check the entries in fstab
To check the size of all mounted partitions use the below command
#df -Th
Check the exact filesystem by below command
#cat /etc/fstab
Step 2: Take backup of both the partition to prevent from Data Lose
Take backup of /linux partition
#rsync -avzxl /linux /linux.backup
Take backup of /Database partition
#rsync -avzxl /Database /Database.backup
Step 3: Change the mount point in the fstab and mount all partitions
Edit the fstab entry by swapping the mount point of /Database and /linux
#vi /etc/fstab
Verify it by using the below command
#cat /etc/fstab
Mount all the partition in the /etc/fstab by using the below command
Verify all the partitions are mounted by the below command
#df -Th
Step 4: Check the data present the folders and swap it
Find out what are the data present in both the folders by the below command
#ls -l /Database
#ls -l /linux
We found that data are placed in wrong folder because of mount point changing, then don’t wait swap the data
#mv /Database/* /Database.2ndbackup
#mv /linux/* /Database/
#mv /Database.2ndbackup /linux
Again check out what are the data present in both the folders by the below command
#ls -l /Database
#ls -l /linux
Every thing looks fine now. Verify the folder size by below command
#df -Th
