How do i assign a new disk/LV to the root folder "/" which has been already mounted by sdb2 partition? - linux

Question

[root#my-linux-vm ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 4K 0 disk
sda 8:0 0 16G 0 disk
└─sda1 8:1 0 16G 0 part
sdb 8:16 0 10G 0 disk
├─sdb1 8:17 0 2M 0 part
└─sdb2 8:18 0 10G 0 part /
sdc 8:32 0 12G 0 disk
└─sdc1 8:33 0 12G 0 part
└─vg_new_root-lv0 252:0 0 11G 0 lvm
sr0 11:0 1 1024M 0 rom
Given the above partition/disk situation,
can i mount the 'vg_new_root-lv0' LV onto the root ("/")folder in order to extend the root capacity beyond sdb2 space?

Answer 1

The short answer is No, based on your current configuration.
Due to the fact that the / root filesystem is not part of LVM there is no easy way to expand its capacity.
My suggestion would be to run a disk space script to confirm what is the directory or service that is using a significant amount of the disk space and then (if possible) move that data into the new sdc1 drive / vg_new_root-lv0 Logical Volume, it needs to be formatted and mounted to be ready to use, once mounted you can stop your application and then move all the data to that new filesystem (i.e /mnt/data), after you confirm that the data has been moved you can then start your application, test and then remove the data from the original location under the sdb2 disk / root / filesystem to free up space.
Run the below one liner to get a disk usage report and confirm what you can remove / compress / move.
echo -n "Type Filesystem: ";read FS;NUMRESULTS=20;resize;clear;date;df -h $FS;echo "Largest Directories:"; du -x $FS 2>/dev/null| sort -rnk1| head -n $NUMRESULTS| awk '{printf "%d MB %s\n", $1/1024,$2}';echo "Largest Files:"; nice -n 19 find $FS -mount -type f -ls 2>/dev/null| sort -rnk7| head -n $NUMRESULTS|awk '{printf "%d MB\t%s\n", ($7/1024)/1024,$NF}'