# How volumes are attached and mapped for Amazon EC2 Windows instances
How volumes are attached and mapped for Windows instances

**Note**  
This topic applies to Windows instances only.

Your Windows instance comes with an EBS volume that serves as the root volume. If your Windows instance uses AWS PV or Citrix PV drivers, you can optionally add up to 25 volumes, making a total of 26 volumes. For more information, see [Amazon EBS volume limits for Amazon EC2 instances](volume_limits.md).

Depending on the instance type of your instance, you'll have from 0 to 24 possible instance store volumes available to the instance. To use any of the instance store volumes that are available to your instance, you must specify them when you create your AMI or launch your instance. You can also add EBS volumes when you create your AMI or launch your instance, or attach them while your instance is running.

When you add a volume to your instance, you specify the device name that Amazon EC2 uses. For more information, see [Device names for volumes on Amazon EC2 instances](device_naming.md). AWS Windows Amazon Machine Images (AMIs) contain a set of drivers that are used by Amazon EC2 to map instance store and EBS volumes to Windows disks and drive letters.

**Topics**
+ [Map NVME disks to volumes](windows-list-disks-nvme.md)
+ [Map non-NVME disks to volumes](windows-list-disks.md)

# Map NVMe disks on Amazon EC2 Windows instance to volumes
Map NVME disks to volumes

With [Nitro-based instances](instance-types.md#instance-hypervisor-type), EBS volumes are exposed as NVMe devices. This topic explains how to view the **NVMe disks** that are available to the Windows operating system on your instance. It also shows how to map those NVMe disks to the underlying Amazon EBS volumes and the device names specified for the block device mappings used by Amazon EC2.

**Topics**
+ [

## List NVMe disks
](#windows-disks-nvme)
+ [

## Map NVMe disks to volumes
](#ebs-nvme-volume-map)

## List NVMe disks


You can find the disks on your Windows instance using Disk Management or Powershell.

------
#### [ Disk Management ]

**To find the disks on your Windows instance**

1. Log in to your Windows instance using Remote Desktop. For more information, see [Connect to your Windows instance using RDP](connecting_to_windows_instance.md).

1. Start the Disk Management utility.

1. Review the disks. The root volume is an EBS volume mounted as `C:\`. If there are no other disks shown, then you didn't specify additional volumes when you created the AMI or launched the instance.

   The following is an example that shows the disks that are available if you launch an `r5d.4xlarge` instance with two additional EBS volumes.  
![\[Disk Management with a root volume, two instance store volumes, and two EBS volumes.\]](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/images/disk_management_nvme.png)

------
#### [ PowerShell ]

The following PowerShell script lists each disk and its corresponding device name and volume. It is intended for use with [Nitro-based instances](instance-types.md#instance-hypervisor-type), which use NVMe EBS and instance store volumes.

Connect to your Windows instance and run the following command to enable PowerShell script execution.

```
Set-ExecutionPolicy RemoteSigned
```

Copy the following script and save it as `mapping.ps1` on your Windows instance.

```
# List the disks for NVMe volumes

function Get-EC2InstanceMetadata {
    param([string]$Path)
    (Invoke-WebRequest -Uri "http://169.254.169.254/latest/$Path").Content 
}

function GetEBSVolumeId {
    param($Path)
    $SerialNumber = (Get-Disk -Path $Path).SerialNumber
    if($SerialNumber -clike 'vol*'){
        $EbsVolumeId = $SerialNumber.Substring(0,20).Replace("vol","vol-")
    }
    else {
       $EbsVolumeId = $SerialNumber.Substring(0,20).Replace("AWS","AWS-")
    }
    return $EbsVolumeId
}

function GetDeviceName{
    param($EbsVolumeId)
    if($EbsVolumeId -clike 'vol*'){
    
        $Device  = ((Get-EC2Volume -VolumeId $EbsVolumeId ).Attachment).Device
        $VolumeName = ""
    }
     else {
        $Device = "Ephemeral"
        $VolumeName = "Temporary Storage"
    }
    Return $Device,$VolumeName
}

function GetDriveLetter{
    param($Path)
    $DiskNumber =  (Get-Disk -Path $Path).Number
    if($DiskNumber -eq 0){
        $VirtualDevice = "root"
        $DriveLetter = "C"
        $PartitionNumber = (Get-Partition -DriveLetter C).PartitionNumber
    }
    else
    {
        $VirtualDevice = "N/A"
        $DriveLetter = (Get-Partition -DiskNumber $DiskNumber).DriveLetter
        if(!$DriveLetter)
        {
            $DriveLetter = ((Get-Partition -DiskId $Path).AccessPaths).Split(",")[0]
        } 
        $PartitionNumber = (Get-Partition -DiskId $Path).PartitionNumber   
    }
    
    return $DriveLetter,$VirtualDevice,$PartitionNumber

}

$Report = @()
foreach($Path in (Get-Disk).Path)
{
    $Disk_ID = ( Get-Partition -DiskId $Path).DiskId
    $Disk = ( Get-Disk -Path $Path).Number
    $EbsVolumeId  = GetEBSVolumeId($Path)
    $Size =(Get-Disk -Path $Path).Size
    $DriveLetter,$VirtualDevice, $Partition = (GetDriveLetter($Path))
    $Device,$VolumeName = GetDeviceName($EbsVolumeId)
    $Disk = New-Object PSObject -Property @{
      Disk          = $Disk
      Partitions    = $Partition
      DriveLetter   = $DriveLetter
      EbsVolumeId   = $EbsVolumeId 
      Device        = $Device 
      VirtualDevice = $VirtualDevice 
      VolumeName= $VolumeName
    }
	$Report += $Disk
} 

$Report | Sort-Object Disk | Format-Table -AutoSize -Property Disk, Partitions, DriveLetter, EbsVolumeId, Device, VirtualDevice, VolumeName
```

Run the script as follows:

```
PS C:\> .\mapping.ps1
```

The following is example output for an instance with a root volume, two EBS volumes, and two instance store volumes.

```
Disk Partitions DriveLetter EbsVolumeId           Device    VirtualDevice VolumeName
---- ---------- ----------- -----------           ------    ------------- ----------
   0          1 C           vol-03683f1d861744bc7 /dev/sda1 root
   1          1 D           vol-082b07051043174b9 xvdb      N/A
   2          1 E           vol-0a4064b39e5f534a2 xvdc      N/A
   3          1 F           AWS-6AAD8C2AEEE1193F0 Ephemeral N/A           Temporary Storage
   4          1 G           AWS-13E7299C2BD031A28 Ephemeral N/A           Temporary Storage
```

If you did not configure your credentials for Tools for Windows PowerShell on the Windows instance, the script cannot get the EBS volume ID and uses N/A in the `EbsVolumeId` column.

------

## Map NVMe disks to volumes


You can use the [ Get-Disk](https://learn.microsoft.com/en-us/powershell/module/storage/get-disk) command to map Windows disk numbers to Amazon EBS volumes and Amazon EC2 instance store volumes.

```
PS C:\> Get-Disk
Number Friendly Name Serial Number                    HealthStatus         OperationalStatus      Total Size Partition
                                                                                                             Style
------ ------------- -------------                    ------------         -----------------      ---------- ----------
3      NVMe Amazo... AWS6AAD8C2AEEE1193F0_00000001.   Healthy              Online                   279.4 GB MBR
4      NVMe Amazo... AWS13E7299C2BD031A28_00000001.   Healthy              Online                   279.4 GB MBR
2      NVMe Amazo... vol0a4064b39e5f534a2_00000001.   Healthy              Online                       8 GB MBR
0      NVMe Amazo... vol03683f1d861744bc7_00000001.   Healthy              Online                      30 GB MBR
1      NVMe Amazo... vol082b07051043174b9_00000001.   Healthy              Online                       8 GB MBR
```

You can also run the **ebsnvme-id** command to map NVMe disk numbers to EBS volume IDs and device names.

```
PS C:\> C:\PROGRAMDATA\Amazon\Tools\ebsnvme-id.exe
Disk Number: 0
Volume ID: vol-03683f1d861744bc7
Device Name: sda1

Disk Number: 1
Volume ID: vol-082b07051043174b9
Device Name: xvdb

Disk Number: 2
Volume ID: vol-0a4064b39e5f534a2
Device Name: xvdc
```

# Map non-NVMe disks on Amazon EC2 Windows instance to volumes
Map non-NVME disks to volumes

For instances launched from a Windows AMI that uses AWS PV or Citrix PV drivers, you can use the relationships described on this page to map your Windows disks to your instance store and EBS volumes. This topic explains how to view the **non-NVMe disks** that are available to the Windows operating system on your instance. It also shows how to map those non-NVMe disks to the underlying Amazon EBS volumes and the device names specified for the block device mappings used by Amazon EC2.

**Note**  
If you launch an instance If your Windows AMI uses Red Hat PV drivers, you can update your instance to use the Citrix drivers. For more information, see [Upgrade PV drivers on EC2 Windows instances](Upgrading_PV_drivers.md).

**Topics**
+ [

## List non-NVMe disks
](#windows-disks)
+ [

## Map non-NVMe disks to volumes
](#windows-volume-mapping)

## List non-NVMe disks


You can find the disks on your Windows instance using Disk Management or PowerShell.

------
#### [ Disk Management ]

**To find the disks on your Windows instance**

1. Log in to your Windows instance using Remote Desktop. For more information, see [Connect to your Windows instance using RDP](connecting_to_windows_instance.md).

1. Start the Disk Management utility.

   On the taskbar, right-click the Windows logo, and then choose **Disk Management**.

1. Review the disks. The root volume is an EBS volume mounted as `C:\`. If there are no other disks shown, then you didn't specify additional volumes when you created the AMI or launched the instance.

   The following is an example that shows the disks that are available if you launch an `m3.medium` instance with an instance store volume (Disk 2) and an additional EBS volume (Disk 1).  
![\[Disk Management with a root volume, one instance store volume, and one EBS volume.\]](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/images/disk_management.png)

1. Right-click the gray pane labeled Disk 1, and then select **Properties**. Note the value of **Location** and look it up in the tables in [Map non-NVMe disks to volumes](#windows-volume-mapping). For example, the following disk has the location Bus Number 0, Target Id 9, LUN 0. According to the table for EBS volumes, the device name for this location is `xvdj`.  
![\[The location of an EBS volume.\]](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/images/disk_1_location.png)

------
#### [ PowerShell ]

The following PowerShell script lists each disk and its corresponding device name and volume.

**Requirements and limitations**
+ Requires Windows Server 2012 or later.
+ Requires credentials to get the EBS volume ID. You can configure a profile using the Tools for PowerShell, or attach an IAM role to the instance.
+ Does not support NVMe volumes.
+ Does not support dynamic disks.

Connect to your Windows instance and run the following command to enable PowerShell script execution.

```
Set-ExecutionPolicy RemoteSigned
```

Copy the following script and save it as `mapping.ps1` on your Windows instance.

```
# List the disks
function Convert-SCSITargetIdToDeviceName {
  param([int]$SCSITargetId)
  If ($SCSITargetId -eq 0) {
    return "sda1"
  }
  $deviceName = "xvd"
  If ($SCSITargetId -gt 25) {
    $deviceName += [char](0x60 + [int]($SCSITargetId / 26))
  }
  $deviceName += [char](0x61 + $SCSITargetId % 26)
  return $deviceName
}

[string[]]$array1 = @()
[string[]]$array2 = @()
[string[]]$array3 = @()
[string[]]$array4 = @()

Get-WmiObject Win32_Volume | Select-Object Name, DeviceID | ForEach-Object {
  $array1 += $_.Name
  $array2 += $_.DeviceID
}

$i = 0
While ($i -ne ($array2.Count)) {
  $array3 += ((Get-Volume -Path $array2[$i] | Get-Partition | Get-Disk).SerialNumber) -replace "_[^ ]*$" -replace "vol", "vol-"
  $array4 += ((Get-Volume -Path $array2[$i] | Get-Partition | Get-Disk).FriendlyName)
  $i ++
}

[array[]]$array = $array1, $array2, $array3, $array4

Try {
  $InstanceId = Get-EC2InstanceMetadata -Category "InstanceId"
  $Region = Get-EC2InstanceMetadata -Category "Region" | Select-Object -ExpandProperty SystemName
}
Catch {
  Write-Host "Could not access the instance Metadata using AWS Get-EC2InstanceMetadata CMDLet.
Verify you have AWSPowershell SDK version '3.1.73.0' or greater installed and Metadata is enabled for this instance." -ForegroundColor Yellow
}
Try {
  $BlockDeviceMappings = (Get-EC2Instance -Region $Region -Instance $InstanceId).Instances.BlockDeviceMappings
  $VirtualDeviceMap = (Get-EC2InstanceMetadata -Category "BlockDeviceMapping").GetEnumerator() | Where-Object { $_.Key -ne "ami" }
}
Catch {
  Write-Host "Could not access the AWS API, therefore, VolumeId is not available.
Verify that you provided your access keys or assigned an IAM role with adequate permissions." -ForegroundColor Yellow
}

Get-disk | ForEach-Object {
  $DriveLetter = $null
  $VolumeName = $null
  $VirtualDevice = $null
  $DeviceName = $_.FriendlyName

  $DiskDrive = $_
  $Disk = $_.Number
  $Partitions = $_.NumberOfPartitions
  $EbsVolumeID = $_.SerialNumber -replace "_[^ ]*$" -replace "vol", "vol-"
  if ($Partitions -ge 1) {
    $PartitionsData = Get-Partition -DiskId $_.Path
    $DriveLetter = $PartitionsData.DriveLetter | Where-object { $_ -notin @("", $null) }
    $VolumeName = (Get-PSDrive | Where-Object { $_.Name -in @($DriveLetter) }).Description | Where-object { $_ -notin @("", $null) }
  }
  If ($DiskDrive.path -like "*PROD_PVDISK*") {
    $BlockDeviceName = Convert-SCSITargetIdToDeviceName((Get-WmiObject -Class Win32_Diskdrive | Where-Object { $_.DeviceID -eq ("\\.\PHYSICALDRIVE" + $DiskDrive.Number) }).SCSITargetId)
    $BlockDeviceName = "/dev/" + $BlockDeviceName
    $BlockDevice = $BlockDeviceMappings | Where-Object { $BlockDeviceName -like "*" + $_.DeviceName + "*" }
    $EbsVolumeID = $BlockDevice.Ebs.VolumeId
    $VirtualDevice = ($VirtualDeviceMap.GetEnumerator() | Where-Object { $_.Value -eq $BlockDeviceName }).Key | Select-Object -First 1
  }
  ElseIf ($DiskDrive.path -like "*PROD_AMAZON_EC2_NVME*") {
    $BlockDeviceName = (Get-EC2InstanceMetadata -Category "BlockDeviceMapping")."ephemeral$((Get-WmiObject -Class Win32_Diskdrive | Where-Object { $_.DeviceID -eq ("\\.\PHYSICALDRIVE" + $DiskDrive.Number) }).SCSIPort - 2)"
    $BlockDevice = $null
    $VirtualDevice = ($VirtualDeviceMap.GetEnumerator() | Where-Object { $_.Value -eq $BlockDeviceName }).Key | Select-Object -First 1
  }
  ElseIf ($DiskDrive.path -like "*PROD_AMAZON*") {
    if ($DriveLetter -match '[^a-zA-Z0-9]') {
      $i = 0
      While ($i -ne ($array3.Count)) {
        if ($array[2][$i] -eq $EbsVolumeID) {
          $DriveLetter = $array[0][$i]
          $DeviceName = $array[3][$i]
        }
        $i ++
      }
    }
    $BlockDevice = ""
    $BlockDeviceName = ($BlockDeviceMappings | Where-Object { $_.ebs.VolumeId -eq $EbsVolumeID }).DeviceName
  }
  ElseIf ($DiskDrive.path -like "*NETAPP*") {
    if ($DriveLetter -match '[^a-zA-Z0-9]') {
      $i = 0
      While ($i -ne ($array3.Count)) {
        if ($array[2][$i] -eq $EbsVolumeID) {
          $DriveLetter = $array[0][$i]
          $DeviceName = $array[3][$i]
        }
        $i ++
      }
    }
    $EbsVolumeID = "FSxN Volume"
    $BlockDevice = ""
    $BlockDeviceName = ($BlockDeviceMappings | Where-Object { $_.ebs.VolumeId -eq $EbsVolumeID }).DeviceName
  }
  Else {
    $BlockDeviceName = $null
    $BlockDevice = $null
  }
  New-Object PSObject -Property @{
    Disk          = $Disk;
    Partitions    = $Partitions;
    DriveLetter   = If ($DriveLetter -eq $null) { "N/A" } Else { $DriveLetter };
    EbsVolumeId   = If ($EbsVolumeID -eq $null) { "N/A" } Else { $EbsVolumeID };
    Device        = If ($BlockDeviceName -eq $null) { "N/A" } Else { $BlockDeviceName };
    VirtualDevice = If ($VirtualDevice -eq $null) { "N/A" } Else { $VirtualDevice };
    VolumeName    = If ($VolumeName -eq $null) { "N/A" } Else { $VolumeName };
    DeviceName    = If ($DeviceName -eq $null) { "N/A" } Else { $DeviceName };
  }
} | Sort-Object Disk | Format-Table -AutoSize -Property Disk, Partitions, DriveLetter, EbsVolumeId, Device, VirtualDevice, DeviceName, VolumeName
```

Run the script as follows:

```
PS C:\> .\mapping.ps1
```

The following is example output.

```
Disk  Partitions  DriveLetter   EbsVolumeId             Device      VirtualDevice   DeviceName              VolumeName
----  ----------  -----------   -----------             ------      -------------   ----------              ----------
   0           1            C   vol-0561f1783298efedd   /dev/sda1   N/A             NVMe Amazon Elastic B   N/A
   1           1            D   vol-002a9488504c5e35a   xvdb        N/A             NVMe Amazon Elastic B   N/A
   2           1            E   vol-0de9d46fcc907925d   xvdc        N/A             NVMe Amazon Elastic B   N/A
```

If you did not provide your credentials on the Windows instance, the script cannot get the EBS volume ID and uses N/A in the `EbsVolumeId` column.

------

## Map non-NVMe disks to volumes


The block device driver for the instance assigns the actual volume names when mounting volumes.

**Topics**
+ [

### Instance store volumes
](#instance-store-volume-map)
+ [

### EBS volumes
](#ebs-volume-map)

### Instance store volumes


The following table describes how the Citrix PV and AWS PV drivers map non-NVMe instance store volumes to Windows volumes. The number of available instance store volumes is determined by the instance type. For more information, see [Instance store volume limits for EC2 instances](instance-store-volumes.md).


| Location | Device name | 
| --- | --- | 
| Bus Number 0, Target ID 78, LUN 0 | xvdca | 
| Bus Number 0, Target ID 79, LUN 0 | xvdcb | 
| Bus Number 0, Target ID 80, LUN 0 | xvdcc | 
| Bus Number 0, Target ID 81, LUN 0 | xvdcd | 
| Bus Number 0, Target ID 82, LUN 0 | xvdce | 
| Bus Number 0, Target ID 83, LUN 0 | xvdcf | 
| Bus Number 0, Target ID 84, LUN 0 | xvdcg | 
| Bus Number 0, Target ID 85, LUN 0 | xvdch | 
| Bus Number 0, Target ID 86, LUN 0 | xvdci | 
| Bus Number 0, Target ID 87, LUN 0 | xvdcj | 
| Bus Number 0, Target ID 88, LUN 0 | xvdck | 
| Bus Number 0, Target ID 89, LUN 0 | xvdcl | 

### EBS volumes


The following table describes how the Citrix PV and AWS PV drivers map non-NVME EBS volumes to Windows volumes.


| Location | Device name | 
| --- | --- | 
| Bus Number 0, Target ID 0, LUN 0 | /dev/sda1 | 
| Bus Number 0, Target ID 1, LUN 0 | xvdb | 
| Bus Number 0, Target ID 2, LUN 0 | xvdc | 
| Bus Number 0, Target ID 3, LUN 0 | xvdd | 
| Bus Number 0, Target ID 4, LUN 0 | xvde | 
| Bus Number 0, Target ID 5, LUN 0 | xvdf | 
| Bus Number 0, Target ID 6, LUN 0 | xvdg | 
| Bus Number 0, Target ID 7, LUN 0 | xvdh | 
| Bus Number 0, Target ID 8, LUN 0 | xvdi | 
| Bus Number 0, Target ID 9, LUN 0 | xvdj | 
| Bus Number 0, Target ID 10, LUN 0 | xvdk | 
| Bus Number 0, Target ID 11, LUN 0 | xvdl | 
| Bus Number 0, Target ID 12, LUN 0 | xvdm | 
| Bus Number 0, Target ID 13, LUN 0 | xvdn | 
| Bus Number 0, Target ID 14, LUN 0 | xvdo | 
| Bus Number 0, Target ID 15, LUN 0 | xvdp | 
| Bus Number 0, Target ID 16, LUN 0 | xvdq | 
| Bus Number 0, Target ID 17, LUN 0 | xvdr | 
| Bus Number 0, Target ID 18, LUN 0 | xvds | 
| Bus Number 0, Target ID 19, LUN 0 | xvdt | 
| Bus Number 0, Target ID 20, LUN 0 | xvdu | 
| Bus Number 0, Target ID 21, LUN 0 | xvdv | 
| Bus Number 0, Target ID 22, LUN 0 | xvdw | 
| Bus Number 0, Target ID 23, LUN 0 | xvdx | 
| Bus Number 0, Target ID 24, LUN 0 | xvdy | 
| Bus Number 0, Target ID 25, LUN 0 | xvdz |