Author: jamrockbrown

How to unmount a LUN or detach a datastore device from ESXi hosts

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:

  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 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

  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.

    For more information on the esxcfg-scsidevscommand, see Identifying disks when working with VMware ESX/ESXi (1014953).

  3. 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

  4. 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 0

    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 unmountcommand.

  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 -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.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 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
  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:
    1. 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

    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

Uploading files to a vSphere service might fail

Details

Initiating a file upload to either a content library or datastore, or attempting to deploy an OVF or OVA template, might result in the operation failing with an error:

The operation failed for an undetermined reason. Typically this problem occurs due to certificates that the browser does not trust. If you are using self-signed or custom certificates, open the URL below in a new browser tab and accept the certificate, then retry the operation.

https://target-ip

To resolve this issue follow the solutions below as per the scenario.

Solution 1:

  1. From a client system Web browser, go to the base URL of the vCenter Server system or the vCenter Server Virtual Appliance without appending port numbers or ‘vsphere-client‘ extension.
    For example:
    https://vcenter.domain.com/
  2. Click the Download trusted root CA certificates link at the bottom of the grey box on the right and download the file.
  3. Change the extension of the file to .zip. The file is a ZIP file of all root certificates and all CRLs in the VMware Endpoint Certificate Store (VECS).
  4. Extract the contents of the ZIP file. The result is a .certs folder that contains two types of files. Files with a number as the extension (.0, .1, and so on) are root certificates. Files with an extension that starts with an r (.r0,. r1, and so on) are CRL files associated with a certificate.
  5. Install the certificate files as trusted certificates by following the process that is appropriate for your operating system.
    For most Microsoft Windows systems, you can follow the instructions at Manage trusted root certificates.
Note: Some datastores with special characters will not allow you to download files. In some cases, removing the special characters from the datastore name has allowed us to download. This is a rare problem and the above solution is more likely.

Solution 2: In some cases the serenity database becomes corrupt, reset serenity DB to resolve the issue following the below steps:

  • In appliance:
    # service vsphere-client stop
    rm -rf /etc/vmware-vsphere-client/SerenityDB/serenity/*
    # service vsphere-client start
  • In vSphere 6.5 and higher
    # service-control –stop vsphere-client
    rm -rf /etc/vmware-vsphere-client/SerenityDB/serenity/*
    # service-control –start vsphere-client
  • In Windows:
    # cd <C:\Program Files\VMware\vCenter Server\bin>
    # service-control –stop vspherewebclientsvc
  • Delete the contents of the folders below.
    <C:\programdata\vmware\vCenterServer\data\vSphere Web Client\SerenityDB\serenity>
    #service-control –start vspherewebclientsvc

Creating a new virtual disk for an existing Linux virtual machine 

To create a new virtual disk for an existing Linux virtual machine:
  1. Log in as root on your Linux virtual machine.
  2. Run this command and make note of the sdxentries

    ls /dev/sd*

  3. Log in to the vCenter Server using the vSphere Client.
  4. In the vSphere Client inventory, right-click the virtual machine and select Edit Settings.
  5. Click the Hardware tab and click Add.
  6. Select Hard Disk and click Next.
  7. Complete the wizard.
  8. Reboot the Linux virtual machine.
  9. Log in using the root credentials.
  10. Running the command ls /dev/sd* will now return a new entry.
  11. Create an ext3 file system on the new disk using the new sdx from step 10.

    mkfs -t ext3 /dev/sdx

    You may see an alert that you are performing this operation on an entire device, not a partition. That is correct, as you created a single virtual disk of the intended size. This is assuming you have specified the correct device.

    Caution
    : Ensure you have selected the right device, there is no undo.

  12. Run the fdisk command to verify the existence of the disk you created:

    fdisk -l

  13. Run this command to create a mount point for the new disk:

    mkdir / New_Directory_Name

  14. Run this command to display the current /etc/fstab:

    cat /etc/fstab

  15. Using a text editor, edit fstab and add this line to add the disk to /etc/fstab so that it is available across reboots:

    /dev/sdx /New_Directory_Name ext3 defaults 1 3

    Note: Use a Linux text editor of your choice.

  16. Restart the Linux virtual machine and the new disk is now available.

Creating virtual machines in VMware Workstation

To create a virtual machine using VMware Workstation:
  1. Launch VMware Workstation.
  2. Click New Virtual Machine.
  3. Select the type of virtual machine you want to create and click Next:

    Note: Your choice depends partially on the hardware version you want your virtual machine to have. For more information, see Virtual machine hardware versions (1003746).

    • Custom: This gives you an option to create a virtual machine and choose its hardware compatibility. You can choose from Workstation 14.x, Workstation 12.x, Workstation 11.x, Workstation 10.x, Workstation 9.x, Workstation 8.x, Workstation 6.5 -7.x, Workstation 6, Workstation 5, and Workstation 4.
    • Typical: This creates a virtual machine which has the same hardware version as the version of Workstation you are using. If you are using Workstation 8.x, it creates a virtual machine with hardware version 8. If you are using Workstation 6.5.x or 7.x, a virtual machine with hardware version 7 is created.
  4. Click Next.
  5. Select your guest operating system (OS), then click Next. You can install the OS using:
    • An installer disc (CD/DVD)
    • An installer disc image file (ISO)
  6. Click Next.
  7. Enter your Product Key.
  8. Create a user name and password.
  9. Click Next.
  10. Enter a virtual machine name and specify a location for virtual machine files to be saved, click Next.
  11. Establish the virtual machine’s disk size, select whether to store the virtual disk as a single file or split the virtual disk into 2GB files, click Next.
  12. Verify the other configuration settings for your virtual machine:
    • Memory – change the amount of memory allocated to the virtual machine.
    • Processors – change the number of processors, number of cores per processor, and the virtualization engine.
    • CD / DVD – with advanced settings where you can choose between SCSI, IDE.
    • Network adapter – configure it to bridge, NAT, or Host-only mode, or customize where you can choose between 0 to 9 adapters.
    • USB Controller.
    • Sound card.
    • Display – enable 3D graphics.
  13. Click Finish.
  14. When the virtual machine is powered on, the VMware Tools installation starts. You are prompted to restart your virtual machine once the Tools installation completes.