Use ext4 Linux File System on Engine Yard

Updated: July 23rd, 2020

note By default all new environments will use ext4 formatting, so this feature is used to force ext4 on older environments where needed. This article is no longer relevant and is kept for historical purposes.

This is Early Access documentation for the ext4 Linux File System feature. 

The ext4 or fourth extended filesystem is a journaling file system for Linux, developed as the successor to ext3. Enabling the ext4 Linux File System Early Access feature provides you the option of having the /data and /db volumes formatted with ext4 instead of ext3. 

Get started with ext4 Linux File System on Engine Yard

This document describes how to use the ext4 Linux File System feature on Engine Yard.

• Prerequisites
• Enable the ext4 Linux File System feature
• Configure ext4 Linux File System
• More information

Get help or provide feedback

If you have any issues or questions about this Early Access feature, use the Early Access Feature Feedback forum.

Prerequisites

• This article assumes you already have an Engine Yard account. If not, see Sign up for an Engine Yard Account.
• Create an on-demand backup of your database or confirm that you have an acceptable database backup.
• You must upgrade to the February 13th, 2014 cookbook release.

Enable the ext4 Linux File System feature

You need to enable the Early Access feature before you can participate in the program.

To enable the ext4 Linux File System Early Access feature

1. Log in to your Engine Yard account.

2. On the dashboard, click Tools > Early Access on the toolbar.

   

3. Next to the ext4 Linux File System feature, click Enable.

   The related functionality becomes available.

Configure ext4 Linux File System

When you create a new Engine Yard environment, simply select the "Format volumes using ext4 filesystem" checkbox to configure this feature.

Configure for an Existing Engine Yard Environment

Note: Existing environments cannot be upgraded from ext3 to ext4.

After enabling this Early Access feature, you can now format the /data and /db volumes with ext4. This process will delete everything on the existing ext3 volumes.

Important: Before you start this configuration process, create an on-demand backup of your database or confirm that you have an acceptable database backup.

To configure ext4 Linux File System

These directions indicate the dump step for the database after the environment has been rebuilt, the dump step should occur as step 1 before stopping the target environment

1. Create an on-demand backup of your database
2. Terminate your environment.
3. Edit the environment and select "Format volumes using ext4 filesystem"
4. Restart your environment with a new volume. Important: Do NOT restart from a snapshot.
5. Restore your database

To reduce downtime consider building a new environment from new volumes in parallel and:

1. Validate the new deployment with test data
2. Place application in maintenance mode
3. Dump the database from the source and restore it to the destination
4. Use the Elastic IP migration tool to swap the public IP's between the source and destination environments

note this technique can be used in conjunction with major stack upgrades (v1->v4) or major database version upgrades.

More information

This table provides other resources related to ext4 Linux File System.

If you have feedback or questions about this page, add a comment below. If you need help, submit a ticket with Engine Yard Support.