This article provides steps to unmount a LUN from an ESXi 5.x/6.x host, which includes unmounting the file system and detaching the datastore/storage device. These steps must be performed for each ESXi host. Easy to follow Step-by-Step Guide: How to Unmount a LUN or Detach a Datastore.
Unmounting a LUN using the command line
To unmount a LUN from an ESXi 5.x/6.x host using the command line:
- If the LUN is an RDM, skip to step 4. Otherwise, to obtain a list of all datastores mounted to an ESXi host, run this command:# esxcli storage filesystem list
You see output, which lists all VMFS datastores, 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 - 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.
For more information on the esxcfg-scsidevscommand, see Identifying disks when working with VMware ESX/ESXi (1014953).
- Unmount the datastore by running this command:# esxcli storage filesystem unmount [-uUUID | -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 - To verify that the datastore is unmounted, run this command:# esxcli storage filesystem list
You see output 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 0The 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 unmountcommand.
- To detach the device/LUN, run this command:# esxcli storage core device set –state=off -d NAA_ID
- To verify that the device is offline, run this command:# esxcli storage core device list -dNAA_ID
You see output, which shows that the Status of the disk is off, 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.020000000060a98000572d54724a346557335067514c554e202020Running 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 - 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.
- To rescan all devices on the ESXi host, run this command:# esxcli storage core adapter rescan [ -Avmhba# | –all ]
The devices are automatically removed from the Storage Adapters.
Notes:
- A rescan must be run on all hosts that had visibility to the removed LUN.
- 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 this command:# esxcli storage core device set –state=on -d NAA_ID
- 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:
- To list the permanently detached devices:# esxcli storage core device detached list
You see output similar to:
Device UID State
—————————- —–
naa.50060160c46036df50060160c46036df off
naa.6006016094602800c8e3e1c5d3c8e011 off - 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
- To list the permanently detached devices:# esxcli storage core device detached list
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