Designlet: Create iSCSI VMFS Datastore using Oracle Cloud Block Storage Volume


Oracle Cloud has announced the support of Oracle Cloud Infrastructure (OCI) Block Storage through iSCSI for Oracle Cloud VMware Solution (OCVS). OCI Block storage provides the capability to provision OCI block storage volumes through the iSCSI protocol. With this, you can attach the block storage volumes to all the ESXi instances that are part of OCVS VMware SDDC and provision a new VMFS datastore.

This capability allows you to scale the VMware SDDC Storage without adding additional ESXi instances, thus significantly bringing down the cost of running VMware SDDC in OCI.

Now, Oracle Cloud VMware Solution officially supports all three storage providers, i.e., vSAN, NFS, and VMFS (iSCSI). The vSAN datastore is the locally attached high-performing storage for OCVS VMware SDDC, whereas NFS and Block Storage (iSCSI) can be an on-demand secondary storage option for OCVS VMware SDDC.

Summary and Considerations

Use Case

A secondary storage option for Oracle Cloud VMware Solution backed by iSCSI OCI Block Storage Volume.


  1. Oracle Cloud Infrastructure (OCI)

OCI Block Storage Volume

  1. OCVS VMware SDDC

Software iSCSI Initiator

Dynamic Discovery Path

General Considerations/Recommendations

You can consider configuring the iSCSI VMFS datastore if you need to extend storage resources on OCVS VMware SDDC.

  • OCI Block Storage volume is NVMe backed storage service and can be accessed via the iSCSI protocol.
  • Ideal for most workloads, including the ones that require high IOPS.


Performance Characteristics

OCVS offers two compute shapes, and both the shapes support Ultra High-Performance Storage Tier for block storage volume. The OCI Block Storage Volume supports a maximum of 300,000 IOPS per volume with Ultra High-Performance Storage Tier. 

Cost Implications

Check the block storage pricing here

Document Reference

OCI Block Volume Performance

Last Updated

Oct 2022



In a traditional VMware environment, there are certain prerequisites that you need to take care of from a networking and storage perspective. The good news for OCVS customers is that networking requirements between ESXi host instances and iSCSI Target are already taken care of. Hence, it does not require any additional steps on the networking part to get this working. This document does not describe iSCSI implementation in detail, but you can refer to the following documentation to understand more about iSCSI SAN in the VMware environment. Using ESXi with iSCSI SAN.


Create Block Storage Volume

  1. Go to the hamburger menu from Oracle Cloud Console.
  2. Go to Storage
  3. Select Block Storage Volume
  4. Select the appropriate compartment
  5. Click on Create Block Volume
  6. Provide the required Inputs
  1. Name – Block Volume Name
  2. Select Compartment
  3. Select the Availability Domain
  4. Volume Size and Performance, either you can select the default, or you can customize the values as per the requirement.
  5. Select the Backup Policy
  6. Cross-region replication – By default, set to Off. Keep it as is.
  7. Select the encryption
  8. Click on Create Block Volume

Attach Block Volume to OCVS ESXi Instances

  1. Click on the newly created block volume
  2. Click on Attached Instances
  3. Click Attach to Instance
  4. Set the attachment type as iSCSI
  5. Set the Access Type as Read/Write – Shareable

Note: Read/Write – Shareable enables multiple instances to execute read/write operations simultaneously on the volume. This access type should only be used with the clustered file system to prevent data corruption.

In the VMware environment, ESXi hosts require the access type as read/write – shareable on the block volume to create a VMware File System (VMFS) datastore.

  1. Select Instance, In the drop-down select the ESXi host instance.
  2. Enable the CHAP credential if required.
  3. Leave the device path blank.
  4. Click on Attach.
  5. Repeat the same process to attach block volume on all the ESXi instances that are part of VMware SDDC. 

iSCSI Command and Mount Details

  1. Once all the ESXi instances are attached, Click on iSCSI Command & Information.
  2. Note down the IP address and port details.
  3. Verify these details for all the ESXi instances. Use the same IP address and port information to configure the dynamic discovery. We will use the same information in VMware SDDC in the next step.

Create VMFS Datastore

  1. Log in to the vCenter Server.
  2. Click on one of the ESXi hosts.
  3. Click on Configure
  4. Select Storage Adapter and ensure Software iSCSi Initiator is provisioned. Please note that OCVS VMware SDDC instances have the software iSCSI initiator built in.
  5. Select the vmhba adapter that has the model type iSCSI Software Adapter.
  6. Under the same adapter, Click on Dynamic Discovery.
  7. Click Add, Provide the iSCSI IP address and Port details as captured from the Block Volume Attachment.
  8. Rescan Adapter. You can see a new Storage Device/LUN after the successful configuration of the dynamic discovery.
  9. Repeat the same process on all the ESXi hosts.
  10. Right, Click on the Cluster Object. Go to Storage – New Storage.
  11. Select VMFS
  12. Provide Datastore Name.
  13. Select the ESXi host from the drop-down.
  14. Select the Storage Device
  15. Select VMFS Version as VMFS 6
  16. Keep the partition details to their default settings.
  17. Click Finish.

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