When your ESXi host connects to block-based storage systems, LUNs or storage devices that support ESXi become available to the host.

After the devices get registered with your host, you can display all available local and networked devices and review their information. If you use third-party multipathing plug-ins, the storage devices available through the plug-ins also appear on the list.
Note: If an array supports implicit asymmetric logical unit access (ALUA) and has only standby paths, the registration of the device fails. The device can register with the host after the target activates a standby path and the host detects it as active. The advanced system /Disk/FailDiskRegistration parameter controls this behavior of the host.

For each storage adapter, you can display a separate list of storage devices available for this adapter.

Generally, when you review storage devices, you see the following information.

Storage Device Information Description
Name Also called Display Name. It is a name that the ESXi host assigns to the device based on the storage type and manufacturer. Generally, you can change this name to a name of your choice. See Rename Storage Devices.
Identifier A universally unique identifier that is intrinsic to the device. See ESXi Storage Device Names and Identifiers.
Operational State Indicates whether the device is attached or detached. See Detach Storage Devices.
LUN Logical Unit Number (LUN) within the SCSI target. The LUN number is provided by the storage system. If a target has only one LUN, the LUN number is always zero (0). See Target and Device Representations.
Type Type of device, for example, disk or CD-ROM.
Drive Type Information about whether the device is a flash drive or a regular HDD drive. For information about flash drives and NVMe devices, see Using Flash Devices with ESXi Hosts.
Transport Transportation protocol your host uses to access the device. The protocol depends on the type of storage being used. See What Types of Physical Storage Does ESXi Support.
Capacity Total capacity of the storage device.
Owner The plug-in, such as the NMP or a third-party plug-in, that the host uses to manage paths to the storage device. See Using Pluggable Storage Architecture and Path Management with ESXi.
Hardware Acceleration Information about whether the storage device assists the host with virtual machine management operations. The status can be Supported, Not Supported, or Unknown. See Storage Hardware Acceleration in vSphere.
Sector Format Indicates whether the device uses a traditional, 512n, or advanced sector format, such as 512e or 4Kn. See Device Sector Formats.
Location A path to the storage device in the /vmfs/devices/ directory.
Partition Format A partition scheme used by the storage device. It can be of a master boot record (MBR) or GUID partition table (GPT) format. The GPT devices can support datastores greater than 2 TB. See Device Sector Formats.
Partitions Primary and logical partitions, including a VMFS datastore, if configured. See Working with Datastores in vSphere Storage Environment.
Multipathing Policies Path Selection Policy and Storage Array Type Policy the host uses to manage paths to storage. See Understanding Multipathing and Failover in the ESXi Environment.
Paths Paths used to access storage and their status. See Deactivate Storage Paths.

Display Storage Devices for an ESXi Host

Display all storage devices available to a ESXi host. If you use any third-party multipathing plug-ins, the storage devices available through the plug-ins also appear on the list.

The Storage Devices view allows you to list the hosts' storage devices, analyze their information, and modify properties.

Procedure

  1. In the vSphere Client, navigate to the ESXi host.
  2. Click the Configure tab.
  3. Under Storage, click Storage Devices.

    All storage devices available to the host are listed in the Storage Devices table.

  4. To view details for a specific device, select the device from the list.
  5. Use the icons to perform basic storage management tasks.

    Availability of specific icons depends on the device type and configuration.

  6. Use the following tabs to access additional information and modify properties for the selected device.

    Tab

    Description

    Properties

    View device properties and characteristics. View and modify multipathing policies for the device. See Viewing and Managing Storage Paths on ESXi Hosts.

    Paths

    Display paths available for the device. Deactivate or enable a selected path. See Deactivate Storage Paths.

    Partition Details

    Displays information about partitions and their formats.

Display Storage Devices for an Adapter

Display a list of storage devices accessible through a specific storage adapter on an ESXi host.

Procedure

  1. In the vSphere Client, navigate to the ESXi host.
  2. Click the Configure tab.
  3. Under Storage, click Storage Adapters.
    All storage adapters installed on the host are listed in the Storage Adapters table.
  4. Select the adapter from the list and click the Devices tab.
    Storage devices that the host can access through the adapter are displayed.
  5. Use the icons to perform basic storage management tasks.

    Availability of specific icons depends on the device type and configuration.

    Icon Description
    Refresh Refresh information about storage adapters, topology, and file systems.
    Detach Detach the selected device from the host.
    Attach Attach the selected device to the host.
    Rename Change the display name of the selected device.
    Turn On LED Turn on the locator LED for the selected devices.
    Turn Off LED Turn off the locator LED for the selected devices.
    Mark as Flash Disk Mark the selected devices as flash disks.
    Mark as HDD Disk Mark the selected devices as HDD disks.
    Mark as Local Mark the selected devices as local for the host.
    Mark as Remote Mark the selected devices as remote for the host.
    Erase Partitions Erase partitions on the selected devices.
    Mark as Perennially Reserved Mark the selected device as perennially reserved.
    Unmark as Perennially Reserved Clear the perennial reservation from the selected device.

Device Sector Formats

ESXi supports storage devices with traditional and advanced sector formats. In storage, a sector is a subdivision of a track on a storage disk or device. Each sector stores a fixed amount of data.

This table introduces different storage device formats that ESXi supports.

Storage Device Format ESXi Software Emulation Logical Sector Size Physical Sector Size VMFS Datastore
512n N/A 512 512 VMFS5 and VMFS6 (default)
512e N/A 512 4096 VMFS5 and VMFS56 (default)
Note: Local 512e storage devices do not support VMFS5.
4Kn 512 4096 4096 VMFS6

512-Byte Native Format

ESXi supports traditional 512n storage devices that use a native 512-bytes sector size.

512-Byte Emulation Format

Due to the increasing demand for larger capacities, the storage industry has introduced advanced formats, such as 512-byte emulation, or 512e. 512e is the advanced format in which the physical sector size is 4096 bytes, but the logical sector emulates 512-bytes sector size. Storage devices that use the 512e format can support legacy applications and guest operating systems. These devices serve as an intermediate step to 4Kn sector drives.

4K Native Format with Software Emulation

Another advanced format that ESXi supports is the 4Kn sector technology. In the 4Kn devices, both physical and logical sectors are 4096 bytes (4 KiB) in length. The device does not have an emulation layer, but exposes its 4Kn physical sector size directly to ESXi.

ESXi detects and registers the 4Kn devices and automatically emulates them as 512e. The device is presented to upper layers in ESXi as 512e. But the guest operating systems always see it as a 512n device. You can continue using existing VMs with legacy guest OSes and applications on the host with the 4Kn devices.

When you use 4Kn devices, the following considerations apply:
  • ESXi supports only local 4Kn SAS and SATA HDDs.
  • ESXi does not support 4Kn SSD and NVMe devices, or 4Kn devices as RDMs.
  • ESXi can boot only from a 4Kn device with UEFI.
  • You can use the 4Kn device to configure a coredump partition and coredump file.
  • Only the NMP plug-in can claim the 4Kn devices. You cannot use the HPP to claim these devices.
  • With vSAN, you can use only the 4Kn capacity HDDs for vSAN Hybrid Arrays. For information, see the Administering VMware vSAN documentation.
  • Due to the software emulation layer, the performance of the 4Kn devices depends on the alignment of the I/Os. For best performance, run workloads that issue mostly 4K aligned I/Os.
  • Workloads accessing the emulated 4Kn device directly using scatter-gather I/O (SGIO) must issue I/Os compatible with the 512e disk.

Determine Device Format

To determine whether the device uses the 512n, 512e, or 4Kn format, run the following command.

esxcli storage core device capacity list

The following sample output shows the format type.
Device                Physical Blocksize  Logical Blocksize  Logical Block Count         Size  Format Type
--------------------  ------------------  -----------------  -------------------  -----------  -----------
naa.5000xxxxxxxxx36f                 512                512           2344225968  1144641 MiB  512n
naa.5000xxxxxxxxx030                4096                512           3516328368  1716957 MiB  4Kn SWE
naa.5000xxxxxxxxx8df                 512                512           2344225968  1144641 MiB  512n
naa.5000xxxxxxxxx4f4                4096                512           3516328368  1716957 MiB  4Kn SWE