Resize a VM disk online and on-the-fly

resize-vm-disk-online.sh

## 
## Prerequisites:
##  - already resized disk on the VM host
## 
## Notes:
##  - I assume that we have three partitions (primary (root fs), extended, logical (swap))
##  - I assume that we move swap out of the extended partition and convert to a normal primary one
##  - I also assume that we place swap at the end of the disk
## 

ssh _VM_
  
sudo swapoff -a
  
sudo parted /dev/_DISK_
parted> p
  
# now check if the new size is displayed already, otherwise halt the server and start it again
  
parted> rm 5
parted> rm 2
parted> p
  
# check if swap and logical partition is gone
  
parted> resizepart 1
  
# be sure to get the right End for the new partition minus the size of the new swap (2 GB i.e.)
  
End? [xyGB]? _NEWSIZE_GB
parted> p
  
# check if the root part has the right size and create swap with the right START and END
  
parted> mkpart primary linux-swap _START_ _END_
parted> p
  
# check if there are 2 primary partitions now
  
parted> quit
  
cat /proc/partitions
  
# check if the kernel updated the partition sizes correctly, otherwise issue "sudo partprobe" or cold-reboot again, then continue
  
sudo resize2fs /dev/_PARTITION_
df -h /dev/_PARTITION_
  
mkswap /dev/_PARTITION_
  
# write out the UID and edit it in /etc/fstab for the correct swap
  
vi /etc/fstab