Extreme Persistent Disk

For high-end performance-critical applications, use Extreme Persistent Disk volumes. Extreme Persistent Disk volumes feature higher maximum IOPS and throughput than other Persistent Disk volumes, and let you provision IOPS and capacity separately. Extreme Persistent Disk is available in all zones.

When you create an Extreme Persistent Disk, you can provision 2,500 to 120,000 IOPS. If you need more than 125,000 IOPS, we recommend Google Cloud Hyperdisk. Hyperdisk offers the highest IOPS and throughput in Compute Engine and is available on the latest machine types.

This document explains several restrictions of using Extreme Persistent Disk, considerations for reaching maximum possible performance levels, and how to provision IOPS using the Google Cloud console, the gcloud CLI or REST.

Before you begin

• If you haven't already, then set up authentication. Authentication is the process by which your identity is verified for access to Google Cloud services and APIs. To run code or samples from a local development environment, you can authenticate to Compute Engine by selecting one of the following options:
  

  Select the tab for how you plan to use the samples on this page:

  Console

  When you use the Google Cloud console to access Google Cloud services and APIs, you don't need to set up authentication.

  gcloud

  1. Install the Google Cloud CLI. After installation, initialize the Google Cloud CLI by running the following command:

     gcloud init

     If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

  2. Set a default region and zone.

  REST

  To use the REST API samples on this page in a local development environment, you use the credentials you provide to the gcloud CLI.

  Install the Google Cloud CLI. After installation, initialize the Google Cloud CLI by running the following command:

  gcloud init

  If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

  For more information, see Authenticate for using REST in the Google Cloud authentication documentation.

Machine shape support

You can use N2, M2 and M3 machine series with Extreme Persistent Disk. N2 VMs require at least 64 vCPUs.The following is list of machine types that support the maximum performance levels offered by Extreme Persistent Disk:

• N2:

  • n2-*-64
  • n2-*-80
  • n2-*-96
  • n2-*-128

• M2:

  • m2-*-208
  • m2-*-416

• M3:

  • m3-*-32
  • m3-*-64

All other machine types are not supported for production use. If you'd like to use an unsupported machine type, we recommend Hyperdisk instead.

N2 VMs with 64 or 80 vCPUs require the Intel Ice Lake CPU platform to reach the stated performance limits. N2 VMs using Intel Cascade Lake CPU platforms will have slightly lower performance. For more information, see setting the minimum CPU platform for VM instances.

Performance limits for Extreme Persistent Disk

The following table lists the performance limits for the supported machine types.

Performance limits and workload patterns

To reach the maximum performance levels offered by Extreme Persistent Disk volumes, you must consider the following workload parameters:

• I/O size: Maximum IOPS limits assume that you are using an I/O size of 4 or 8 KB. Maximum throughput limits assume that you are using an I/O size of 1 MB.
• Queue length: Queue length is the number of pending requests for a persistent disk. To reach maximum performance limits, you must tune your queue length according to the I/O size, IOPS, and latency sensitivity of your workload. Optimal queue length varies for each workload, but typically should be larger than 128.
• Working set size: Working set size is the amount of data of a disk being accessed within a short period of time. To achieve optimal performance, limit working set sizes to less than 1.5 TB.
• Concurrent use of other persistent disks: Extreme Persistent Disk volumes share the per-VM maximum IOPS and throughput limits with all other persistent disks attached to the same VM. When monitoring the performance of your Extreme Persistent Disk volumes, take into account any I/O requests that you are sending to other disks attached to the same VM.

Other restrictions

• Extreme Persistent Disk volumes are zonal only. You can't create regional Extreme Persistent Disks.
• You cannot attach multiple VM instances in read-only mode to an Extreme Persistent Disk volume.
• You cannot create an image or machine image from an extreme persistent disk.
• You can resize an Extreme Persistent Disk only once in a 6 hour period.

Throughput

For Extreme Persistent Disk volumes, throughput scales with the number of IOPS you provision at a rate of 256 KB of throughput per I/O. However, throughput is ultimately capped by per-instance limits that depend on the number of vCPUs on the VM instance to which your extreme disks are attached.

Throughput for Extreme Persistent Disk volumes isn't full duplex. The maximum throughput limits listed in this document apply to the sum total of read and write throughput.

Provisioning IOPS

To provision IOPS to match your workload requirements, do the following:

1. Note the IOPS requirement of your workload.
2. Determine the IOPS required to fulfill the throughput requirements of your workload.
   • Required IOPS = throughput in KB per second / 256
3. Set the provisioned IOPS to the larger of the two numbers.

gcloud compute disks create DISK_NAME \
  --size=DISK_SIZE \
  --type=pd-extreme \
  --provisioned-iops=IOPS_LIMIT

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/disks

{
 "name": "DISK_NAME",
 "type": "zones/ZONE/diskTypes/pd-extreme"
 "provisionedIops": "IOPS_LIMIT"
}

What's next?

• Review disk pricing information.
• Review disk performance metrics.
• Learn how to add an Extreme Persistent Disk volume to your VM.
• Learn how to clone an Extreme Persistent Disk volume.