Today we are excited to announce a new capability for Oracle Cloud Infrastructure Block Volumes: Paravirtualized attachments for VMs! Attach a block volume to a VM and it becomes available as a storage device immediately ready to use for your workloads. To access your volume, you don't have to run iSCSI configuration commands anymore!
In the context of block volumes, paravirtualization is a light virtualization technique where a VM (guest OS) utilizes hypervisor APIs to access remote storage directly as if it were a local device. This is more efficient than full virtualization. On the other hand, iSCSI block storage attachment utilizes the internal storage stack in the guest OS and network hardware virtualization to access block volumes. Hypervisor is not involved in the iSCSI attachment process.
When a volume is attached to a VM, the default attachment type is determined based on the OS image you select. You have the option of one-click paravirtualized volume attachment, or more fine-granular control provided by iSCSI attachment.
All new Oracle Linux images published since December 2017 and Windows images published since February 2018 will have the paravirtualized block volume attachment option for VMs. Older Oracle images will continue to use iSCSI. Your custom images inherit the volume attachment type from the VM the custom image was captured from.
Paravirtualized attachment simplifies the process of configuring your block storage by removing the extra commands needed before accessing a volume. However, due to the overhead of virtualization, this reduces the maximum IOPS performance for larger block volumes compared to iSCSI attachments. If storage IOPS performance is of paramount importance for your workloads, you can continue to experience the industry-leading performance Oracle Cloud Infrastructure Block Volumes offer by using iSCSI attachments.
Here is an example of how easy it is to attach a block volume with paravirtualized attachment type:
Once you attach the volume, it is ready to use right away, in this example /dev/sdb. No more iSCSI configuration!
Similar to attaching a volume, detaching a volume is also easy with paravirtualized attachments. Just detach your volume when you don't need it anymore, and it is gone from your compute instance:
Paravirtualized attachments are currently available for Oracle Cloud Infrastructure VM compute instances only. Bare Metal instances continue to use iSCSI attachments ensuring the best storage performance you expect from Oracle Block Volumes.
We are also announcing that you can now attach a volume with read-only access, in addition to the read/write access that was available before. With this capability, you can safeguard data against accidental or malicious modifications by an untested or untrusted application, by directly controlling the access at the block storage device level. By default, volume attachments are set to read-write access. A volume with a read-only attachment still supports all existing management functionality, such as direct disk-to-disk block volume clones and backups.
We strive to bring value to our customers by listening to their feedback. Removing the iSCSI configuration steps with volume attachments and enabling read-only attachments are a few examples showing our commitment to you. Stay tuned for additional features and capabilities in this space. The Oracle team and I value your feedback as we continue to make our service the best in the industry. Send me your thoughts on how we can continue to improve, or if you want more details on any topic.
Product Management - Oracle Cloud Infrastructure