Determine the boot mode of an instance
The boot mode of an instance is displayed in the Boot mode field in the Amazon EC2 console, and by the
currentInstanceBootMode parameter in the AWS CLI.
When an instance is launched, the value for its boot mode parameter
is determined by the value of the boot mode
parameter of the AMI used to launch it, as follows:
-
An AMI with a boot mode parameter of uefi creates an instance with a
currentInstanceBootMode parameter of uefi.
-
An AMI with a boot mode parameter of legacy-bios creates an instance with a
currentInstanceBootMode parameter of
legacy-bios.
-
An AMI with a boot mode parameter of uefi-preferred creates an instance with
a currentInstanceBootMode parameter of uefi if the
instance type supports UEFI; otherwise, it creates an instance with a
currentInstanceBootMode parameter of
legacy-bios.
-
An AMI with no boot mode parameter value creates an instance with a
currentInstanceBootMode parameter value that is dependent on
whether the AMI architecture is ARM or x86 and the supported boot mode of the
instance type. The default boot mode is uefi on Graviton instance types, and
legacy-bios on Intel and AMD instance types.
- Console
-
To determine the boot mode of an instance (console)
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the navigation pane, choose Instances, and then select your
instance.
-
On the Details tab, inspect the Boot mode
field.
- AWS CLI
-
To determine the boot mode of an instance (AWS CLI)
Use the describe-instances command to determine
the boot mode of an instance. You can also determine the boot mode of
the AMI that was used to the create the instance.
C:\> aws ec2 describe-instances --region us-east-1 --instance-ids i-1234567890abcdef0
{
"Reservations": [
{
"Groups": [],
"Instances": [
{
"AmiLaunchIndex": 0,
"ImageId": "ami-0e2063e7f6dc3bee8",
"InstanceId": "i-1234567890abcdef0",
"InstanceType": "m5.2xlarge",
...
},
"BootMode": "uefi",
"CurrentInstanceBootMode": "uefi"
}
],
"OwnerId": "1234567890",
"ReservationId": "r-1234567890abcdef0"
}
]
}
- PowerShell
-
To determine the boot mode of an instance (Tools for PowerShell)
Use the Get-EC2Image Cmdlet to determine the
boot mode of an instance. You can also determine the boot mode of the
AMI that was used to the create the instance.
Get-EC2Image (AWS Tools for Windows PowerShell)
(Get-EC2Instance -InstanceId i-1234567890abcdef0).Instances | Format-List BootMode, CurrentInstanceBootMode, InstanceType, ImageId
BootMode : uefi
CurrentInstanceBootMode : uefi
InstanceType : c5a.large
ImageId : ami-0265446f88eb4021b
In the output, the following parameters describe the boot mode:
