**Purpose**: The purpose of this workflow is to illustrate the process of expanding storage for a Linux server acting as a GuestVM. We want the VM to have more storage space, so this document will go over the steps to expand that usable space. !!! info "Assumptions" It is assumed you are using a RHEL variant of linux such as Rocky Linux. This should apply to any version of Linux, but was written in a Rocky Linux 9.4 lab environment. This document also assumes you did not enable Logical Volume Management (LVM) when deploying your server. If you did, you will need to perform additional (undocumented) LVM-specific steps after increasing the space following this document. ## Increase GuestVM Virtual Disk Size This part should be fairly straight-forward. Using whatever hypervisor is running the Linux GuestVM, expand the disk space of the disk to the desired size. ## Extend Partition Table This step goes over how to increase the usable space of the virtual disk within the GuestVM itself after it was expanded within the hypervisor. !!! warning "Be Careful" When you follow these steps, you will be deleting the existing partition and immediately re-creating it. If you do not use the **EXACT SAME** starting sector for the new partition, you will destroy data. Be sure to read every annotation next to each command to fully understand what you are doing. === "Using GDISK" ``` sh sudo dnf install gdisk -y gdisk /dev/ # (1) p # (2) d # (3) 4 # (4) n # (5) 4 # (6) (Just press ENTER) # (7) (Just press ENTER) # (8) (Just press ENTER) # (9) w # (10) ``` !!! info "Details" 1. The first command needs you to enter the disk identifier. In most cases, this will likely be the first disk, such as `/dev/sda`. You do not need to indicate a partition number in this step, as you will be asked for one in a later step after identifying all of the partitions on this disk in the next command. 2. This will list all of the partitions on the disk. 3. This will ask you for a partition number to delete. Generally this is the last partition number listed. In the example below, you would type `4` then press ++enter++ to schedule the deletion of the partition. === "Using FDISK w/ LVM" ``` sh # Resize Partition of Disk in PV Group fdisk /dev/hda # Use pvdisplay to get the disk identifier p # List Partitions d # Delete the partition 2 # Assume Partition 2 (e.g. /dev/hda2) n # Make a new Partition p # Primary Partition Type Starting Sector: Ending Sector: w # Commit changes to the disk # Probe the new partition partprobe /dev/hda # Reboot the Server reboot # Resize PV Device pvdisplay # Note Current Size then reference it later pvresize /dev/hda2 pvdisplay # To Confirm size Increased # Extend the Logical Volume for the Target Disk lvextend -l +100%FREE /dev/VolGroup00/LogVol00 # Get this from running lvdisplay to find the correct LV # Resize the Filesystem of the OS resize2fs /dev/VolGroup00/LogVol00 # Validate Space increased df -h ``` ``` Command (? for help): p Disk /dev/sda: 2147483648 sectors, 1024.0 GiB Model: Virtual Disk Sector size (logical/physical): 512/4096 bytes Disk identifier (GUID): 8A5C2469-B07B-42AC-8E57-E756E62D37D1 Partition table holds up to 128 entries Main partition table begins at sector 2 and ends at sector 33 First usable sector is 34, last usable sector is 2147483614 Partitions will be aligned on 2048-sector boundaries Total free space is 1073743838 sectors (512.0 GiB) Number Start (sector) End (sector) Size Code Name 1 2048 1230847 600.0 MiB EF00 EFI System Partition 2 1230848 3327999 1024.0 MiB 8300 3 3328000 19826687 7.9 GiB 8200 4 19826688 1073741790 502.5 GiB 8300 Linux filesystem ``` 4. See the previous annotation for details on what entering `4` does in this context. 5. This tells gdisk to create a new partition. 6. This tells gdisk to re-make partition 4 (the one we just deleted in the example). 7. We just want to leave this as the default. In my example, it would look like this: `First sector (34-2147483614, default = 19826688) or {+-}size{KMGTP}: 19826688` 8. We just want to leave this as the default. In my example, it would look like this: `Last sector (19826688-2147483614, default = 2147483614) or {+-}size{KMGTP}: 2147483614` 9. Just leave this as-is and press ++enter++ without entering any values. Assuming you are using XFS, as this guide was written for, the default "Linux Filesystem" is what you want for XFS. 10. This will write the changes to the partition table making them reality instead of just staging the changes. **Point of No Return**: When you press `w` then ++enter++ the changes will be written to disk, meaning there is no turning back unless you have full GuestVM backups with something like Veeam Backup & Replication. Be certain the first and last sector values are correctly configured before proceeding. ## Detect the New Partition Sizes At this point, the operating system wont detect the changes without a reboot, so we are going to force the operating system to detect them immediately with the following commands to avoid a reboot. ``` sh sudo partprobe sudo partx -u /dev/ sudo xfs_growfs / ``` ??? bug "Partition Not Expanded?" If you notice the partition still has not expanded to the desired size, you may have no choice but to reboot the server, then re-run the `gdisk` commands a second time. In my lab environment, it didn't work until I rebooted. This might have been a hiccup on my end, but it's something to keep in mind if you run into the same issue of the size not changing. ## Validate Storage Expansion At this point, you can leverage `lsblk` or `df -h` to determine if the usable storage space was successfully increased or not. In this example, you can see that I increased my storage space from 512GB to 1TB. !!! example "Example Command Output" Command: `lsblk | grep "sda4"` ``` └─sda4 8:4 0 1014.5G 0 part / ``` Command: `df -h | grep "sda4"` ``` /dev/sda4 1015G 145G 871G 15% / ```