How to Update iSCSI Backup Storage Capacity After Expansion

Discovered Version：v9.0.0

Question

I partitioned a 1TB LUN on the NAS storage management side and mounted it to Vinchin using iSCSI as backup storage. After that, I expanded the LUN size to 2TB on the storage side, but the corresponding storage size did not change in the Vinchin storage management interface, even after I clicked 'Sync'.

Answer

Issue Description

An iSCSI LUN may be expanded on the storage system. Vinchin may still show the old capacity on the web interface. This happens because the Linux partition and the XFS file system do not grow automatically.

Resolution

You can folow the below steps to expand the ISCSI storage manually

IMPORTANT
This guide is for reference in a test environment only. For a production environment, contact Vinchin Technical Support. A support engineer must check the environment and perform the operation. Do not perform these steps by yourself in production.

Step 1. Find the iSCSI disk and mount point

On the Vinchin web interface, open Resources > Storage. Expand the iSCSI storage entry. Record the Disk Path and the backup node. Then log in to that backup node.

Note: Replace `/dev/sdX` with the actual disk identifier identified from the `lsblk` output.

Run the command: lsblk

Check the output carefully.

/dev/sdX is the disk, /dev/sdX1 is the partition, and /backup_storage/<storage-id> is the mount point.

Step 2. Verify the partition table type of /dev/sdX (DOS or GPT)

Run the command: fdisk -l /dev/sdX

Check the output for Disklabel type: gpt or Disklabel type: dos. The commands vary slightly depending on the partition table type.

Step 3. Expand the partition
Scenario 1: Disk uses GPT partition table (Most iSCSI backends use GPT)

Run the command: parted /dev/sdX

Execute the following commands inside the parted interactive session:

(parted) print                           # Confirm the partition number of sdX1 is 1

(parted) resizepart 1 100%       # Expand partition 1 to the end of the disk

(parted) print                           # Verify that sdX1 has been resized to the new capacity

(parted) quit

Scenario 2: Disk uses MBR/DOS partition table

The resizepart command within parted is also supported for MBR disks. Run the same command resizepart 1 100% as shown above.

If you receive the error Not supported for msdos, please contact Vinchin Technical Support for alternative procedures.Step 4. Resize the XFS file system

Step 4. Resize the XFS file system

⚠️ The XFS filesystem can only be expanded while it is mounted

Run the command: xfs_growfs /backup_storage/<storage-id>

Step 5. Refresh storage capacity in Vinchin

Return to the Vinchin web console, navigate to Resources > Storage, click Sync on this iSCSI storage. The updated capacity will be displayed.

Optional Verification 

Run the command below to confirm the new usable capacity:

df -h /backup_storage/<storage-id>