Skip to main content
Version: main

EXT4 Quota Prerequisites

To enable EXT4 Quota on LocalPV Hostpath, certain prerequisites must be met to ensure proper configuration and functionality. This involves installing the quota and e2fsprogs packages, verifying the filesystem type, enabling the project quota feature on the filesystem, and mounting it with the prjquota mount option.

The following steps outline the installation and configuration procedures for both root and data disk filesystems on Ubuntu, Debian, RHEL, and CentOS systems. By completing these steps, you will be ready to enable and manage EXT4 Quotas on your OpenEBS LocalPV Hostpath setup.

Install the quota and e2fsprogs Packages​

The quota package provides the repquota and setquota commands, and e2fsprogs provides the tune2fs, chattr, and lsattr commands.

For Ubuntu/Debian Systems

To install the packages on Ubuntu and Debian systems, execute the following command:

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

For RHEL/CentOS Systems

To install the packages on RHEL/CentOS systems, execute the following command:

$ sudo yum install -y quota e2fsprogs

For Fedora

To install the packages on Fedora, execute the following command:

$ sudo dnf install -y quota e2fsprogs

Check the Filesystem Type​

Verify whether the filesystem of the hostPath directory is EXT4. The default hostPath directory is /var/openebs/local. Execute the following command to check the filesystem type and to identify the device where the filesystem is stored:

$ df -Th /var/openebs/local

Example Output

Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/nvme1n1   ext4  8.0G  959M  7.1G  12% /mnt/data

If the above command fails because the path does not exist yet, execute the following script to check the filesystem type and host device name of the closest existing parent directory:

BASEPATH="/var/openebs/local"

until OUTPUT=$(df -Th $BASEPATH 2> /dev/null)
do
BASEPATH=$(echo "$BASEPATH" | sed 's|\(.*\)/.*|\1|')
done

echo "PATH=${BASEPATH}"
#Final output
echo "$OUTPUT"

Enable the Project Quota Feature on the Filesystem​

Unlike XFS, an EXT4 filesystem must have the project and quota features enabled before project quotas can be used. Filesystems created by older versions of mkfs.ext4 may not have them.

  1. Check the features that are currently enabled on the device.
$ sudo tune2fs -l /dev/nvme1n1 | grep -i "filesystem features"

Example Output

Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file dir_nlink extra_isize metadata_csum

In the example above, project and quota are not present, so they have to be enabled.

  1. Unmount the filesystem. The features cannot be changed while the filesystem is mounted.
$ sudo umount /dev/nvme1n1
  1. Check the filesystem for errors, which is recommended before changing its features.
$ sudo e2fsck -f /dev/nvme1n1
  1. Enable the project and quota features.
$ sudo tune2fs -O project,quota /dev/nvme1n1
  1. Verify that the features are now enabled.
$ sudo tune2fs -l /dev/nvme1n1 | grep -i "filesystem features"

Expected Output

Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file dir_nlink extra_isize metadata_csum quota project
note

The project feature requires the filesystem to have an inode size of 256 bytes or more. This is the default for mkfs.ext4, but filesystems created with a smaller inode size cannot be converted, and have to be recreated. You can check the inode size with sudo tune2fs -l /dev/nvme1n1 | grep -i "inode size".

Mount the Filesystem using the prjquota Mount Option​

  1. Check Existing Mount Options

Ensure that the mount options for the device include prjquota. Execute the following command to verify the mount options for the device (Example: /dev/nvme1n1).

$ sudo mount | grep "^/dev/nvme1n1"

Example Output

/dev/nvme1n1 on /mnt/data type ext4 (rw,relatime)

If the mount options already include prjquota, you can proceed to the next section to Enable EXT4 Quota. If not, continue with the steps below.

  1. Mount the Device with the prjquota Option

If the filesystem is the root filesystem (/), follow the instructions below. If the filesystem is located on a data disk, proceed to the Filesystem on Data Disk section.

Root Filesystem:

To enable prjquota for the root filesystem, modify the GRUB_CMDLINE_LINUX option in the /etc/default/grub file.

  • Edit the file /etc/default/grub.
$ sudo vi /etc/default/grub
  • Locate the line containing the variable GRUB_CMDLINE_LINUX.
GRUB_CMDLINE_LINUX="console=tty0 crashkernel=auto net.ifnames=0 console=ttyS0"
  • Add rootflags=prjquota at the end of the string. If the rootflags option is already present, append prjquota to the list of options.
GRUB_CMDLINE_LINUX="console=tty0 crashkernel=auto net.ifnames=0 console=ttyS0 rootflags=prjquota"

  • Locate the grub.cfg file. The file path may vary based on your OS.

    • /boot/grub2/grub.cfg
    • /boot/efi/EFI/ubuntu/grub.cfg
    • /boot/efi/EFI/debian/grub.cfg
    • /boot/efi/EFI/redhat/grub.cfg
    • /boot/efi/EFI/centos/grub.cfg
    • /boot/efi/EFI/fedora/grub.cfg

  • Create a backup copy of the existing grub.cfg. The sample commands below use the path /boot/grub2/grub.cfg. Replace the paths with your grub.cfg path.

$ sudo cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg.backup
  • Generate a new grub.cfg that includes the changes.
$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
  • Reboot the system.
$ sudo reboot
  • After rebooting, check the mount options again to confirm the changes.
$ sudo mount | grep " / "

Expected Output

/dev/nvme0n1p1 on / type ext4 (rw,relatime,prjquota)

Filesystem on Data Disk​

If the filesystem is located on a data disk, follow these steps:

  1. Unmount the filesystem on the data disk (Replace /dev/nvme1n1 and /mnt/data with your device and mount path).
$ sudo umount /dev/nvme1n1
  1. Mount the disk using the prjquota mount option.
$ sudo mount -o rw,prjquota /dev/nvme1n1 /mnt/data
  1. Verify the mount options.
$ sudo mount | grep "^/dev/nvme1n1"

Expected Output

/dev/nvme1n1 on /mnt/data type ext4 (rw,relatime,prjquota)
  1. Add the prjquota option to the /etc/fstab file for the data disk to make the changes persistent across reboots.
UUID=9cff3d69-3769-4ad9-8460-9c54050583f9 /mnt/data               ext4     defaults,prjquota 0 0

See Also​