Google Cloud Platform

Introducing online resizing of Google Cloud Persistent Disks without downtime

Google Compute Engine provides Persistent Disks to use as the primary block storage for your virtual machine instances. Provisioning the appropriate size of block storage has been a challenge for many cloud and on-premise customers because it requires planning for future data growth and performance needs. When a virtual machine runs out of space, there was no easy way to scale the size of your block storage.

Today we're announcing general availability of online resizing for Persistent Disks. It’s as easy as a button click or a single API call. It doesn’t cause any downtime to Google Compute Engine instances and doesn’t require snapshotting. It applies to all Persistent Disks, including the recently announced 64 TB volumes.

With the introduction of this feature, Persistent Disk capacity planning becomes much simpler. Persistent Disks can be provisioned based on immediate needs and increased in size later when you require more space or performance1. Instead of implementing a complex workflow that would take the system offline — such as snapshot the disk, restore the snapshot to a larger device then bring back online again — there's a single command that makes physical devices larger. The device immediately has higher IOPS and throughput limits. After you resize a disk that's already mounted on a VM instance, resize the file system. Usually it's as simple as running resize2fs on Linux or resizing partitions in Windows Disk Manager.

Internally we've been using online disk resizing with Cloud SQL Second Generation. It has enabled automatic growth of Persistent Disks used by Google Cloud SQL with no downtime.

We hope you enjoy the new feature!

1 Persistent Disk performance depends on the size of the volume and the type of disk you select. Larger volumes can achieve higher I/O levels than smaller volumes.