Managing Configuration Profiles on a Linode

A configuration profile functions as a boot loader for a Linode. It controls general boot settings, including the disk the Linode will boot from, the disks that will be mounted, the kernel that will be used, and the network interfaces on the Linode. Multiple configuration profiles can be created, each one booting from different disks with different settings. This can allow you to try out new Linux distributions without paying for additional Linodes (see Deploy an Image to a Disk on an Existing Linode) or to create custom software testing environments.

Managing Configuration Profiles

The configuration profiles for a Linode can be viewed and managed from the Cloud Manager.

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Configurations tab to view the configuration profiles on a Linode.

From here, a configuration profile can be created using the Add Configuration button. To take action on an certain configuration, locate it within the Configurations table and select from the list of actions, some or all of which may appear within the ellipsis menu:

• Boot: Boots the Linode using the settings defined within the selected configuration profile. See Booting from a Configuration Profile.
• Edit: Modify the settings within a configuration profile. See Editing a Configuration Profile.
• Clone: Clones the configuration profile and the attached disks to any Linode on the same account. See Cloning a Configuration Profile and the Attached Disks.
• Delete: Deletes the configuration profile. See Deleting a Configuration Profile.

Settings

When adding or editing a configuration profile on a Linode, the following settings are available:

• Virtual Machine: VM mode determines whether devices inside your virtual machine are paravirtualized or fully virtualized. Unless there is a specific need to run devices in full virtualization, select paravirtualization. This is required for features like Block Storage.

• Boot Settings:

  • Kernel: Select the version of the Linux kernel that will be used. The options include Grub 2 (for upstream or custom-compiled kernels), a specific Linode supplied kernel, or Direct Disk. For most distributions, its recommended to set this option to Grub 2. See How to Change your Linode’s Kernel.
  • Run Level: Adjust the run level of the OS to allow for advanced diagnostics. Recommended setting: Run Default Level.
  • Memory Limit: Limits the amount of memory that the Linode can use. Recommended setting: Do not set any limits on memory usage.

• Block Device Assignment: Assigns the Linode’s disks to the disk devices in Linux, making them accessible once the Linode has booted up. Up to 8 disks can be assigned (/dev/sda through /dev/sdg), though it’s common to only use the first two devices: /dev/sda as the main disk and /dev/sdb as the swap disk. The Root Device is used to select the primary disk device (commonly /dev/sda), though another predefined device or custom device path can be used.

• Network Interfaces: Assigns either a VLAN or the Public Internet to a network interface in Linux. There are a total of 3 available network interfaces: eth0, eth1, and eth2. If no VLANs are in use, the recommended setting is Public Internet for eth0 and None for all other interfaces. See Getting Started with VLANs.

• Filesystem / Boot Helpers: Various helper tasks that run when the Linode is booted up. Recommended setting for all helpers: Enabled.

  • Enable distro helper: Helps maintain correct inittab/upstart console device.
  • Disable updatedb: Disables updatedb cron job to avoid disk thrashing.
  • Enable modules.dep helper: Creates a module dependency file for the kernel you run.
  • Auto-mount devtmpfs: Controls if pv_ops kernels auto-mount devtmpfs at boot.
  • Auto-configure networking: Automatically configures static networking. See Network Helper.

Creating a Configuration Profile

Making a new configuration profile allows you to create a new and separate boot configuration for your system. You can specify boot settings and disks to mount. Here’s how to create a new configuration profile:

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Configurations tab to view the configuration profiles on a Linode.

3. Select the Add a Configuration link. The Add Linode Configuration form appears:

4. Enter the Label for the new configuration, as well as an optional Comment.

5. Complete the remainder of the form, referencing the Settings section above for additional details and recommended values. For most basic configurations, it’s recommended to adjust the following settings:

   • Kernel: Select Grub 2.
   • Block Device Assignments: Set /dev/sda to the disk you want to use as the primary disk (and boot disk) and set /dev/sdb to the swap disk.

6. Click Add Configuration to create the new configuration profile.

Editing a Configuration Profile

You can edit existing configuration profiles to change boot settings, set other disks to mount, and more. Here’s how to edit a configuration profile:

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Configurations tab to view the configuration profiles on a Linode.

3. Within the Configurations table, locate the configuration profile you wish to modify and click the corresponding Edit button, which may also appear within the ellipsis menu. This displays the Edit Configuration form.

4. Adjust any settings as needed, referencing the Settings section above for additional details and recommended values.

5. Once finished, click Save Changes.

The changes to the configuration profile have been saved. You may need to reboot your Linode to activate the changes.

Booting from a Configuration Profile

You can create and store many different configuration profiles in the Linode Manager, but you can only boot your Linode from one configuration profile at a time. Here’s how to select a configuration profile and boot your Linode from it:

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Configurations tab to view the configuration profiles on a Linode.

3. Within the Configurations table, locate the configuration profile you wish to modify and click the corresponding Boot button, which may also appear within the ellipsis menu.

4. A confirmation dialog window will appear. Click Boot to confirm.

5. The Linode will boot (or reboot) using the selected configuration profile. The progress of the boot can be viewed from the Linode’s status.

You have successfully selected and booted your Linode from a configuration profile.

Determining Which Configuration Profile Was Used

When a Linode is powered on or rebooted, it uses the settings stored within a configuration profile. You can determine which configuration profile was used by looking at the event history. Events are visible within the Activity Feed tab for a particular Linode or within the main Events page for the account.

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Activity Feed tab to view all events for the Linode.

3. Locate the particular boot or reboot event and review the text. The configuration profile used during that boot will be mentioned here.

   Sometimes the boot or reboot event doesn’t list a configuration profile, such as when the Lassie Shutdown Watchdog initiates the event. In this case, look at the most recent reboot or boot event which does include the configuration profile that was used.

Cloning a Configuration Profile and the Attached Disks

A configuration profile, along with any attached disks, can be duplicated to any other Linode on the account. See Cloning a Linode > Cloning to an Existing Linode for instructions.

Deleting a Configuration Profile

You can remove a configuration profile from the Linode Cloud Manager at any time. Here’s how:

1. Log in to the Cloud Manager, click the Linodes link in the sidebar, and select a Linode from the list.

2. Navigate to the Configurations tab to view the configuration profiles on a Linode.

3. Within the Configurations table, locate the configuration profile you wish to modify and click the corresponding Delete button, which may also appear within the ellipsis menu.

4. A confirmation dialog window will appear. Click Delete to confirm.

5. The Linode will boot (or reboot) using the selected configuration profile. The progress of the boot can be viewed from the Linode’s status.