Unmounting a LUN using the command line


To unmount a LUN from an ESXi 5.x host using the command line:

1.     If the LUN is an RDM, skip to step 4. Otherwise, to obtain 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 LUN housing the datastore to be removed, run this command:

# esxcfg-scsidevs -m

This command generates a list of VMFS datastore volumes and their related unique identifiers. Make a note of the unique identifier (
NAA_ID) for the datastore you want to unmount as this will be used later on.
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, you see an error in the VMkernel logs 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 --no-persist flag to the unmount command.
5.     To detach the device/LUN, run the command:

# esxcli storage core device set --state=off -d NAA_ID
6.     To verify that the device is offline, run the 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.     If the device is to be permanently decommissioned, it is now possible to unpresent the LUN from the SAN. For more information, contact your storage team, storage administrator, or 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:

o    A rescan must be run on all hosts that had visibility to the removed LUN.
o    When the device is detached, it stays in an unmounted state even if the device is re-presented (that is, the detached state is persistent). To bring the device back online, the device must 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 host, (that is, the LUN has been or will be destroyed), remove the NAA entries from the host configuration by running these commands:
a.     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
b.     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.

Note: If the device is detached but still presented (step 7 was skipped), the command above fails to permanently remove the device from the system, and the device is automatically re-attached. You must complete step 7 for the device to be permanently removed.

Source: VMware KB

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