Proxmox Backup Server PBS enlarge root disk

How to enlarge an EXT4 or LVM disk on an PBS Proxmox VM 
 Quick TL;DR Guide 
 
 First resize the disk in Proxmox 
 Then in the PBS VM terminal: parted /dev/sdX (probably a)  example

 parted /dev/sda 
print / yes to fix / resizepart Y (probably 1) quit 
 resize2fs /dev/sdXY 
 df -h 
 
 Longer Guide with Explanation 
 First resize the disk in Proxmox: 
 
 At this point you need to START the PBS VM and enter the shell as root follow the below instractions. 
 fdisk -l 
 should show which disks are there. 
 Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 sectors Disk model: QEMU HARDDISK Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX 
 Device       Start       End   Sectors  Size Type /dev/sda1       34      2047      2014 1007K BIOS boot /dev/sda2     2048   1050623   1048576  512M EFI System /dev/sda3  1050624 104855551 103804928 31.5G Linux LVM 
 Disk /dev/mapper/pbs-swap: 3.82 GiB, 4106223616 bytes, 8019968 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes 
 Disk /dev/mapper/pbs-root: 27.67 GiB, 49039802368 bytes, 95780864 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes 
 If you get this message which seems like an error, the resize in Proxmox worked: 
 GPT PMBR size mismatch (167772159 != 314572799) will be corrected by write. The backup GPT table is not on the end of the device. This problem will be corrected by write. 
 The example above is resizing from 30 GB to 50 GB. 
 Now we still have to resize the file system from inside the PBS VM cli terminal : 
 lsblk 
 You should see something like the below. 
 NAME         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS sda            8:0    0   50G  0 disk ├─sda1         8:1    0 1007K  0 part ├─sda2         8:2    0  512M  0 part └─sda3         8:3    0 31.5G  0 part   ├─pbs-swap 252:0    0  3.8G  0 lvm  [SWAP]   └─pbs-root 252:1    0 27.7G  0 lvm  / 
 The run the below command to resize the sda3 
 lvextend -l +100%FREE /dev/mapper/pbs-root
resize2fs /dev/mapper/pbs-root 
 Check that root disk resize all free space 
 df -h 
 Output should be something like this. 
 Filesystem                     

 Size 

 Used

 Avail

 Use%

 Mounted on udev                                 3.9G   

 0 

 3.9G 

 0%

 /dev tmpfs                 

 795M 

 720K   794M 

 1%

   /run /dev/mapper/pbs-root    45G 

   26G 

 18G 

 59%

 / tmpfs                           

 3.9G   

 0 

 3.9G     0%

 /dev/shm tmpfs                         

 

 5.0M     0 

 5.0M 

 0%

 /run/lock tmpfs                 

 795M    0 

 795M 

 0%

 /run/user/0 
 Now your PBS root disk is resize and have free space. 
 
 If you find this helpful or not please leave a comment. 
 Ins0mniA