var filesystem to another disk or partition

Important:Take a complete backup before starting this activity and test these steps in test environment first. Also, perform the below steps in a single-user mode. In the following example, I am moving existing /var to /dev/sdb. 1. Check if the destination disk is presented to the server. # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 20G 0 disk ├─sda1 8:1 0 1G 0 part /boot └─sda2 8:2 0 19G 0 part ├─rhel-root 253:0 0 8G 0 lvm / ├─rhel-swap 253:1 0 1G 0 lvm [SWAP] └─rhel-var 253:1 0 1G 0 lvm /var sdb 8:16 0 5G 0 disk sr0 11:0 1 1024M 0 rom 2. Create LVM structure on the disk /dev/sdb # pvcreate /dev/sdb 3. Create a volume group and a logical volume. # vgcreate vg_var /dev/sdb # lvcreate -n lv_var -l 100%FREE vg_var 4. Create file-system # mkfs.xfs /dev/mapper/vg_var-lv_var 5. Mount the file-system and complete the following steps. # mkdir /var1 # mount /dev/mapper/vg_var-lv_var /var1 # cd /var # cp -dpRx * /var1/ # umount /var1 # cd .. # umount /var # mount /dev/mapper/vg_var-lv_var /var 6. Add an entry to /etc/fstab and restore the selinux context of /var # echo "/dev/mapper/vg_var-lv_var /var xfs defaults 0 0" >> /etc/fstab # restorecon -vvFR /var 7. Make changes to the /etc/default/grub file as shown below. Existing entry: GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet" New entry: GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rd.lvm.lv=vg_var/lv_var rhgb quiet" 8. Changes to /etc/default/grub require rebuilding the grub.cfg file as follows: On BIOS-based machines, issue the following command as root: # grub2-mkconfig -o /boot/grub2/grub.cfg On UEFI-based machines, issue the following command as root: # grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg 9. Take backup of current initramfs file and rebuild initramfs image: # cp /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.$(date +%m-%d-%H%M%S).bak # dracut -v -f /boot/initramfs-$(uname -r).img $(uname -r) 10. Reboot the system #shutdown -r now