Choose a disk type

This document discusses the block storage, commonly referred to asdisksorvolumes, offered by Compute Engine. You can use block storage for bootand data volumes for all compute instances, including virtual machines (VMs),containers, and bare metal instances. This page discusses how to choose block storagefor your compute instances.

The termsdisk,volume, andblock storage volume are synonymousand are used interchangeably across the documentation, the Google Cloud console,the Google Cloud CLI, and the REST API.

About block storage

Google Cloud offers two types of disks, or block storage—temporary anddurable block storage. You can combine these block storage types in a singlecompute instance.

Temporary block storage

Temporary, or ephemeral, block storage offers the fastest performance amongall block storage types, with the tradeoff that thestored data is lost if theVM stops for any reason. Data is lost if you stop, suspend, or restart the VM,or if the VM crashes or fails.

Because of its ephemeral nature, use temporary block storage for onlyscratch data, caches such astempdb for Microsoft SQL Server, or storage forflash-optimized databases. You can't use temporary block storage as a boot volume.

Local SSD, including Titanium SSD, is the temporary block storage offering inGoogle Cloud. Local SSDdisks are physically attached to the server that hosts your instance.

For more information about Local SSD, see the following sections:

Durable block storage

Durable, or persistent, block storage is for data that you want to preserve afteryou stop, suspend or delete the VM, or even if the VM crashes or fails.

HyperdiskandPersistent Disk are the durableblock storage offerings in Google Cloud, but Persistent Disk isn't availablewith the latest machine series. Google recommends using Hyperdiskfor the highest performance and advanced features.

Hyperdisk and Persistent Disk volumes have the following characteristics:

  • Function as physical disks: you can use a Hyperdisk orPersistent Disk volume with compute instance as if it was a physical disk attachedto the instance. However, they are network-attached devices that transmit dataover Google's networks.

  • Portability: Hyperdisk and Persistent Disk volumes are independentof the compute instances that you attach them to. This characteristic meansyou can attach a volume to a running instance without downtime. You can alsodetach the volume to keep your data even after you delete the instance.

  • Security: by default, data is encrypted at rest and in transit. You canalso customize the encryption with your own keys.

  • High availability options: protect your data from zonal failures by replicatingthe volume across two zones.

Differences between Hyperdisk and Persistent Disk

Hyperdisk and Persistent Disk both offer durable, secure, and efficientblock storage, but Google recommends using Hyperdisk.

Hyperdisk offers the following key advantages over Persistent Disk:

  • Customizable performance: You can independently configure the performance andsize of each Hyperdisk volume. Hyperdiskperformance is independent of provisioned capacity. This feature means thatyou can increase or decrease a Hyperdisk volume's performancewithout changing its size.

    Unlike Hyperdisk, Persistent Disk performance depends onprovisioned capacity. Consequently, to improve a Persistent Disk volume'sperformance, you must increase its size.

  • Better overall performance: Hyperdisk has higher IOPS andthroughput limits than Persistent Disk.

Choose a type of block storage

To decide between Local SSD, Hyperdisk and Persistent Disk,follow these steps:

  1. Determine whether you need durable or temporary block storage. Forexample, the boot volume for a compute instance must use durable blockstorage.

  2. If you need to use temporary block storage, use Local SSD if Local SSDis available for your machine series. If you need durable storage, continue to the next step.

  3. If you need to use durable block storage, use Hyperdisk if it'savailable for your machine series.If your machine series doesn't support Hyperdisk, usePersistent Disk.

  4. Choosethe Hyperdisk or Persistent Disk type that best suits yourworkload. To learn about the Hyperdisk and Persistent Disk types, seeChoose a Hyperdisk typeandPersistent Disk types,respectively.

For more information about the features, performance, and durability ofHyperdisk, seeAbout Hyperdisk.For Persistent Disk, seeAbout Persistent Disk.

Alternatives to block storage

In addition to the disks that Google Cloud offers, you can deploy the followingalternative storage solutions on your compute instances.

To compare block storage with the other storage options available inGoogle Cloud, such as Cloud Storage and Filestore,seeReview the storage optionsin the Cloud Architecture Center.

Cost considerations

You're billed for the storage capacity provisioned from when you createa volume until you delete the volume. This charge applies to Local SSD,Persistent Disk, and Hyperdisk.

Costs continue to apply through the following scenarios:

  • Boot volumes that are created automatically when you create a compute instance
  • Durable storage volumes that are attached to a stopped or suspended instance
  • Durable storage volumes that aren't attached to any VM

For Hyperdisk and Extreme Persistent Disk volumes, you'rebilled for the provisioned performance.

For example, since Hyperdisk ML volumes support customizing only throughput,you're billed for the provisioned throughput for a Hyperdisk ML volume, but notfor the IOPS the volume uses.

However, you're billed for the provisioned IOPS and throughput of Hyperdisk Balancedvolumes, because Hyperdisk Balanced volumes support configuring IOPS and throughput.

For more pricing information, seeDisk and image pricing.

What's next

Except as otherwise noted, the content of this page is licensed under theCreative Commons Attribution 4.0 License, and code samples are licensed under theApache 2.0 License. For details, see theGoogle Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.

Last updated 2025-10-24 UTC.