Knowledge Base

Unmounting a LUN checklist

• If the LUN is being used as a VMFS datastore, all objects (such as virtual machines, snapshots, and templates) stored on the VMFS datastore are unregistered or moved to another datastore.
  
  Note: All CD/DVD images located on the VMFS datastore must also be unregistered from the virtual machines.
  
  
• The datastore is not part of a datastore cluster. For more information on datastore clusters, see the vSphere Resource Management Guide.
• The datastore is not managed by Storage DRS. For more information on Storage DRS, see the vSphere Resource Management Guide.
• Storage I/O Control is disabled for the datastore. For more information, see Managing Storage I/O Resources in the vSphere Resource Management Guide.
• The datastore is not used for vSphere HA heartbeat.
• No third-party scripts or utilities running on the ESXi host can access the LUN in question. If the LUN is being used as a datastore, unregister all objects (such as virtual machines and templates) stored on the datastore.
• If the LUN is being used as an RDM, remove the RDM from the virtual machine. Click Edit Settings, highlight the RDM hard disk, and select Remove. Select Delete from disk if it is not already selected, and click OK.
  
  Note: This destroys the mapping file, but not the LUN content.
  
  
• Check if the LUN/Datastore is used as the persistent scratch location for the host. For more information on persistent scratch, see Creating a persistent scratch location for ESXi (1033696).
  
  This PowerCLI script can be used to check the current scratch location:
  
  $vcServer = "vCenter01"
$cluster = "CL01"
$esxCred = Get-Credential
Connect-VIServer $vcServer | Out-Null
#Connect to ESX hosts in cluster
foreach ($esx in Get-Cluster $cluster | Get-VMHost) {
Connect-VIServer $esx -Credential $esxCred | Out-Null
Get-VMHostAdvancedConfiguration -Name "ScratchConfig.ConfiguredScratchLocation"
}

Getting the NAA ID of the LUN to be removed

Unmounting a LUN using the vSphere Client

1. If the LUN is an RDM, skip to Step 2. Otherwise, in the Configuration tab of the ESXi host, click Storage. Right-click the datastore being removed, and click Unmount.
   
   A Confirm Datastore Unmount window appears. When the prerequisite criteria have been passed, click OK.
   
   Note: To unmount a datastore from multiple hosts, in the vSphere Client select Hosts and Clusters, Datastores and Datastore Clusters view (Ctrl+Shift+D). Perform the unmount task and select the appropriate hosts that should no longer access the datastore to be unmounted.
   
   
2. Click the Devices view (under Configuration > Storage):
   
   
   
   
3. Right-click the NAA ID of the LUN (as noted above) and click Detach. A Confirm Device Unmount window is displayed. When the prerequisite criteria have been passed, click OK. Under the Operational State of the Device, the LUN is listed as Unmounted.
   
   Note: The Detach function must be performed on a per-host basis and does not propagate to other hosts in vCenter Server. If a LUN is presented to an initiator group or storage group on the SAN, the Detach function must be performed on every host in that initiator group before unmapping the LUN from the group on the SAN. Failing to follow this step results in an all-paths-down (APD) state for those hosts in the storage group on which Detach was not performed for the LUN being unmapped.
   
   
4. Confirm the LUN has been successfully detached. The LUN can then be safely unpresented from the SAN. For more information, contact your storage array vendor.
5. Perform a rescan on all ESXi hosts which had visibility to the LUN. The device is automatically removed from the Storage Adapters.

1. To list the permanently detached devices:
   
   # esxcli storage core device detached list
   
   The output is similar to:
   
   Device UID                            State
------------------------------------  -----
naa.50060160c46036df50060160c46036df  off
naa.6006016094602800c8e3e1c5d3c8e011  off 
   
   
2. To permanently remove the device configuration information from the system:
   
   # esxcli storage core device detached remove -d NAA_ID
   
   For example:
   
   # esxcli storage core device detached remove -d naa.50060160c46036df50060160c46036df

Unmounting a LUN from the command line

1. If the LUN is an RDM, skip to step 4. Otherwise, to get a list of all datastores mounted to an ESXi host, run the command:
   
   # esxcli storage filesystem list
   
   The output, which lists all VMFS datastores, is similar to:
   
   Mount Point                                       Volume Name UUID                                Mounted Type         Size         Free
------------------------------------------------- ----------- ----------------------------------- ------- ------ -----------  -----------
/vmfs/volumes/4de4cb24-4cff750f-85f5-0019b9f1ecf6 datastore1  4de4cb24-4cff750f-85f5-0019b9f1ecf6    true  VMFS-5   140660178944   94577360896
/vmfs/volumes/4c5fbff6-f4069088-af4f-0019b9f1ecf4 Storage2    4c5fbff6-f4069088-af4f-0019b9f1ecf4    true  VMFS-3   146028888064    7968129024
/vmfs/volumes/4c5fc023-ea0d4203-8517-0019b9f1ecf4 Storage4    4c5fc023-ea0d4203-8517-0019b9f1ecf4    true  VMFS-3   146028888064  121057050624
/vmfs/volumes/4e414917-a8d75514-6bae-0019b9f1ecf4 LUN01      4e414917-a8d75514-6bae-0019b9f1ecf4    true  VMFS-5  146028888064   4266131456
   
   
2. To find the unique identifier of the the LUN housing the datastore to be removed run this command:
   
   # esxcfg-scsidevs -m 
   
   This generates a list of VMFS datastore volumes and their related unique identifiers.  Take note of the unique identifier(NAA_ID) for the datastore you want to unmount as this will be used later on.
   For more information on the esxcfg-scsidevs command see: Identifying disks when working with VMware ESX/ESXi (1014953)
   
   
3. Unmount the datastore by running the command:
   
   # esxcli storage filesystem unmount [-u UUID | -l label | -p path ]
   
   For example, use one of these commands to unmount the LUN01 datastore:
   
   # esxcli storage filesystem unmount -l LUN01
# esxcli storage filesystem unmount -u 4e414917-a8d75514-6bae-0019b9f1ecf4
# esxcli storage filesystem unmount -p /vmfs/volumes/4e414917-a8d75514-6bae-0019b9f1ecf4
   
   Note: If the VMFS filesystem you are attempting to unmount has active I/O or has not fulfilled the prerequisites to unmount the VMFS datastore, the VMkernel logs show an error similar to:
   
   WARNING: VC: 637: unmounting opened volume ('4e414917-a8d75514-6bae-0019b9f1ecf4' 'LUN01') is not allowed.
VC: 802: Unmount VMFS volume f530 28 2 4e414917a8d7551419006bae  f4ecf19b 4 1 0 0 0 0 0 : Busy
   
   
4. To verify that the datastore has been unmounted, run the command:
   
   # esxcli storage filesystem list
   
   The output is similar to:
   
   Mount Point                                       Volume Name UUID                                Mounted Type         Size         Free
------------------------------------------------- ----------- ----------------------------------- ------- ------ -----------  -----------
/vmfs/volumes/4de4cb24-4cff750f-85f5-0019b9f1ecf6 datastore1  4de4cb24-4cff750f-85f5-0019b9f1ecf6    true  VMFS-5   140660178944   94577360896
/vmfs/volumes/4c5fbff6-f4069088-af4f-0019b9f1ecf4 Storage2    4c5fbff6-f4069088-af4f-0019b9f1ecf4    true  VMFS-3   146028888064    7968129024
/vmfs/volumes/4c5fc023-ea0d4203-8517-0019b9f1ecf4 Storage4    4c5fc023-ea0d4203-8517-0019b9f1ecf4    true  VMFS-3   146028888064  121057050624
                                                 LUN01      4e414917-a8d75514-6bae-0019b9f1ecf4   false  VMFS-unknown version    0     0
   
   Note that the Mounted field is set to false, the Type field is set to VMFS-unknown version, and that no Mount Point exists.
   
   Note: The unmounted state of the VMFS datastore persists across reboots. This is the default behavior. If you need to unmount a datastore temporarily you can do so by appending the unmount command with the --no-persist flag.
   
   
   
5. To detach the device/LUN, run this command:
   
   # esxcli storage core device set --state=off -d NAA_ID
   
   
6. To verify that the device is offline, run this command:
   
   # esxcli storage core device list -d NAA_ID
   
   The output, which shows that the status of the disk is off, is similar to:
   
   naa.60a98000572d54724a34655733506751
   Display Name: NETAPP Fibre Channel Disk (naa.60a98000572d54724a34655733506751)
   Has Settable Display Name: true
   Size: 1048593
   Device Type: Direct-Access
   Multipath Plugin: NMP
   Devfs Path: /vmfs/devices/disks/naa.60a98000572d54724a34655733506751
   Vendor: NETAPP
   Model: LUN
   Revision: 7330
   SCSI Level: 4
   Is Pseudo: false
   Status: off
   Is RDM Capable: true
   Is Local: false
   Is Removable: false
   Is SSD: false
   Is Offline: false
   Is Perennially Reserved: false
   Thin Provisioning Status: yes
   Attached Filters:
   VAAI Status: unknown
   Other UIDs: vml.020000000060a98000572d54724a346557335067514c554e202020
   
   Running the partedUtil getptbl command on the device shows that the device is not found.
   
   For example:
   
   # partedUtil getptbl /vmfs/devices/disks/naa.60a98000572d54724a34655733506751

Error: Could not stat device /vmfs/devices/disks/naa.60a98000572d54724a34655733506751 - No such file or directory.
Unable to get device /vmfs/devices/disks/naa.60a98000572d54724a34655733506751
   
   
7. The LUN can now be unpresented from the SAN. For more information, contact your storage array vendor.
8. To rescan all devices on the ESXi host, run the command:
   
   # esxcli storage core adapter rescan [ -A vmhba# | --all ]
   
   The devices are automatically removed from the Storage Adapters.
   
   Notes:
   
   • A rescan must be run on all hosts that had visibility of the removed LUN.
   • When the device is detached, it stays in an unmounted state even if the device is represented (that is, the detached state is persistent). To bring the device back online, the device needs to be attached. To do this via the command line, run the command:
     
     # esxcli storage core device set --state=on -d NAA_ID
     
     
9. If the device is to be permanently decommissioned from an ESXi servers(s), (that is, the LUN has been destroyed), remove the NAA entries from the host configuration by running these commands:
   
   
   1. To list the permanently detached devices:
      
      # esxcli storage core device detached list
      
      The output is similar to:
      
      Device UID                            State
----------------------------  -----
naa.50060160c46036df50060160c46036df  off
naa.6006016094602800c8e3e1c5d3c8e011  off 
      
      
   2. To permanently remove the device configuration information from the system:
      
      # esxcli storage core device detached remove -d NAA_ID
      
      For example:
      
      # esxcli storage core device detached remove -d naa.50060160c46036df50060160c46036df
   
   The reference to the device configuration is permanently removed from the ESXi host's configuration.

Automating detaching datastores using PowerCLI.

Using the PowerCLI

1. Review the VMware Contributed Sample Code disclaimer, and deploy the community-supported PowerCLI script available at Automating Datastore/Storage Device Detachment in vSphere 5.
   
   
2. Ensure that you have already unmounted the desired datastore. For more information, see Unmount VMFS or NFS Datastores in the vSphere 5 Documentation Center.
   
   
3. List all datastores and their attached hosts by running the command:
   
   Get-Datastore | Get-DatastoreMountInfo | Sort Datastore, VMHost | FT –AutoSize
   
   You see an output similar to:
   
   Datastore                VMHost              Lun                                                                        Mounted State  
   ---------                ------              ---                                                                        ------- -----  
   IX2ISCSI01               esx01.vmw.local     naa.5000144f52145699                                                         False Attached
   IX2ISCSI01               esx02.vmw.local     naa.5000144f52145699                                                         False Attached
   IX2ISCSI01               esx03.vmw.local     naa.5000144f52145699                                                         False Attached
   LocalDatastore           esx01.vmw.local     mpx.vmhba1:C0:T0:L0                                                           True Attached
   LocalDatastore           esx02.vmw.local     mpx.vmhba1:C0:T0:L0                                                           True Attached
   esx04-Internal-150GB     esx04.vmw.local     t10.ATA_____GB0160EAPRR_____________________________WCAT25563003________      True Attached
   esx04-Internal-500GB     esx04.vmw.local     t10.ATA_____WDC_WD5000AAKS2D00V1A0________________________WD2DWMAWF0069467    True Attached
   esx03-Internal-150GB     esx03.vmw.local     t10.ATA_____GB0160EAPRR_____________________________WCAT25704089________      True Attached
   esx03-Internal-500GB     esx03.vmw.local     t10.ATA_____WDC_WD5000AAKS2D00YGA0________________________WD2DWCAS85034601    True Attached
   
   
4. Select the appropriate Datastore and record the name beneath the Datastore column, and confirm that the Mounted column contains the value False for all hosts.
   
   
5. Detach the devices from all hosts using the command:
   
   Get-Datastore datastore name| Detach-Datastore
   
   Where datastore name is the name of the Datastore recorded in Step 3.
   
   You see an output similar to:
   
   Detaching LUN naa.5000144f52145699 from host esx01.vmw.local...
   Detaching LUN naa.5000144f52145699 from host esx02.vmw.local...
   Detaching LUN naa.5000144f52145699 from host esx03.vmw.local...

Using the vSphere SDK for Perl

1. Review VMware Contributed Sample Code disclaimer.
   
   
2. Deploy the community-supported Perl script available in the VMware vSphere Blog, Automating Datastore/Storage Device Detachment in vSphere 5.   
   
   Caution: Before proceeding, ensure you have already unmounted the desired datastore.  For more information, see Unmount VMFS or NFS Datastores in the vSphere 5 Documentation Center.
   
   
3. List all datastores and their attached hosts by running this command:
   
   ./lunManagement.pl --server vcenter ip --username user --operation list
   
   Where vcenter ip is the IP address of the vCenter server managing your hosts and user is a user with administrative privileges.
      
4. You will be prompted for a password for the user account used in Step 3. If the correct password is entered, the script generates an output similar to:
   
   Datastore: esx01-local-storage-1 LUN: mpx.vmhba1:C0:T0:L0
           esx01.vmw.local  MOUNTED   ATTACHED
   Datastore: esx02-local-storage-1 LUN: mpx.vmhba1:C0:T0:L0
           esx02.vmw.local  MOUNTED   ATTACHED
   Datastore: iSCSI-1 LUN: naa.600144f0a33bc20000004e9772510001
           esx01.vmw.local  UNMOUNTED   ATTACHED
           esx02.vmw.local  UNMOUNTED   ATTACHED
   Datastore: iSCSI-2 LUN: naa.600144f0a33bc20000004e9772ee0002
           esx01.vmw.local  MOUNTED   ATTACHED
           esx02.vmw.local  MOUNTED   ATTACHED
   Datastore: iSCSI-3 LUN: naa.600144f0a33bc20000004e9773560003
           esx01.vmw.local  MOUNTED   ATTACHED
           esx02.vmw.local  MOUNTED   ATTACHED
   Datastore: iSCSI-4 LUN: naa.600144f0a33bc20000004e9773560004
           esx01.vmw.local  MOUNTED   ATTACHED
           esx02.vmw.local  MOUNTED   ATTACHED
   Datastore: iSCSI-5 LUN: naa.600144f0a33bc20000004e9773570005
           esx01.vmw.local  MOUNTED   ATTACHED
           esx02.vmw.local  MOUNTED   ATTACHED
   
   
5. Confirm that the datastore that you want to detach has been unmounted by observing the UNMOUNTED keyword beneath the applicable datastore name and naa value.
   
   
6. Detach the device across multiple hosts by running this command:
   
   ./lunManagement.pl --server vcenter ip> --username user --operation detach --datastore datastore
   
   Where vcenter ip is the IP address for the vCenter server, user is the user with administrative privileges, and datastore is the name of the datastore identified in Step 4.  
   
   
7. You will be prompted for a password and confirmation that you wish to do the operation. After providing the correct password and acknowledging the warning, the tool generates an output similar to:
   
   Detaching LUN "0200000000600144f0a33bc20000004e9772510001434f4d535441" from Host "esx01.vmw.local" ...
           Successfully detached LUN!
   Detaching LUN "0200000000600144f0a33bc20000004e9772510001434f4d535441" from Host "esx02.vmw.local" ...
           Successfully detached LUN!