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EXT4 Quota with Loop Device

In scenarios where you do not have an existing device formatted with an EXT4 filesystem that has project quota enabled, you can create one on a loop device. This process is particularly useful when the root filesystem cannot be remounted with prjquota, and it allows you to try out project quota enforcement without repartitioning a disk.

This document outlines the steps to create a sparse file, format it with the EXT4 filesystem with the project quota features enabled, and mount it as a loop device at the specified directory, /var/openebs/local.

Create an EXT4 Filesystem at the Basepath as a Loop Device​

  1. Ensure the Required Utilities Are Installed

Before proceeding, ensure that e2fsprogs and quota are installed on your system.

For Ubuntu/Debian-based Systems

sudo apt update
sudo apt-get install -y quota e2fsprogs

For RHEL/CentOS-based Systems

sudo yum install -y quota e2fsprogs
  1. Create the Mount Directory

Create the directory where the filesystem will be mounted.

sudo mkdir -p /var/openebs/local
cd /var/openebs
  1. Create a Sparse File

Create a sparse file of maximum size 1GiB. Use a size that can accommodate the volumes you intend to provision.

sudo dd if=/dev/zero of=ext4.1G bs=1 count=0 seek=1G
  1. Format the Sparse File with EXT4

Format the newly created sparse file with the EXT4 filesystem, enabling the quota and project features that project quotas require.

sudo mkfs.ext4 -F -O quota,project ext4.1G
  1. Mount the Sparse File

Mount the sparse file as a loop device with project quota enabled. This will make the file accessible as the directory /var/openebs/local.

sudo mount -o loop,rw,prjquota ext4.1G /var/openebs/local
  1. Verify the Mount Options
sudo mount | grep "/var/openebs/local"

Expected Output

/var/openebs/ext4.1G on /var/openebs/local type ext4 (rw,relatime,prjquota)

You can now proceed to Enable EXT4 Quota on LocalPV Hostpath.

See Also​