Scaling disk, RAM, and CPU

Review current resources and hosting model

In the Resources tab, you find the Hosting model and Resource allocations tiles. These tiles reflect your current resources and hosting model. Select Configure to adjust the settings in each tile.

Switch to and between hosting models in the UI

In the Resources tab of the UI, select Configure on the Hosting model tile. This opens up a panel where you can adjust your hosting model selection.

The first option available is Select your hosting model. Here, you can switch to a different hosting model.

Below, you will see the options to also adjust the resources of the new hosting model you've selected. Follow the instructions in the previous section, "Scaling in the UI" to adjust your resources.

Click Apply changes to trigger this scaling operation.

Resources and scaling in the CLI

The cdb deployment-groups-set command allows either the total RAM or total disk allocation to be set in MB. For example, to scale the memory of the "example-deployment" to 4096 MB of RAM for each memory member (for a total memory of 12288 MB), you use the command:

ibmcloud cdb deployment-groups-set example-deployment member --memory 12288

Determine the hosting model of your database

Use the following command to review the value of the hostflavor attribute. This will be null if the database is on a deprecated hosting model (not Shared or Isolated Compute).

ibmcloud cdb groups <deployment_id> --json

Switching to and between hosting models in the CLI

If your database is a Shared Compute instance, you can adjust the memory, CPU, and disk options with the following command. If your database is not on Shared Compute, this command will also move a database from a different hosting model to the Shared Compute hosting model.

ibmcloud cdb deployment-groups-set <deploymentid> <groupid> [--memory <val>] [--cpu <val>] [--disk <val>] [--hostflavor multitenant]

For example, use the following to scale to a Shared Compute instance or scale up your Shared Compute instance:

ibmcloud cdb deployment-groups-set crn:abc ... xyz:: member  --memory 24576 --cpu 6  --hostflavor multitenant

If your database is an Isolated Compute instance, memory and CPU are adjusted together by selecting the Isolated Compute size (see all sizes in Table 1). Disk is scaled separately. If your database is not on Isolated Compute, this command will also move a database from a different hosting model to the Isolated Compute hosting model.

Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both an Isolated size selection and separate CPU and RAM allocation selections.

ibmcloud cdb deployment-groups-set <deploymentid> <groupid> [--disk <val>] [--hostflavor <hostflavor>]

For example, use the following to scale to an Isolated Compute instance or scale up your Isolated Compute instance:

ibmcloud cdb deployment-groups-set crn:abc ... xyz:: member  --hostflavor b3c.8x32.encrypted

Determine the hosting model of your database

Use the following command to review the value of the host_flavor attribute. This will be null if the database is on a deprecated hosting model (not Shared or Isolated Compute).

curl -X GET https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups 
-H 'Authorization: Bearer <>' \

Switching to and between hosting models in the API

To scale any Cloud Databases Shared Compute instance, use the the following command, setting host_flavor to multitenant. If your database is not on Shared Compute, this command will also move a database from a different hosting model to the Shared Compute hosting model.

curl -X PATCH https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups/member
-H 'Authorization: Bearer <>'
-H 'Content-Type: application/json'
-d '{"host_flavor": {"id": "multitenant"},
     "cpu": {"allocation_count": 3},
     "memory": {"allocation_mb": 12288}
    }' \

To scale any instance into a Cloud Databases Isolated Compute instance or to scale to a different Isolated Compute size, use the host_flavor parameter, this time set to the desired Isolated Compute size. Available hosting sizes and their host_flavor value parameters are listed in Table 1. For example, {"host_flavor": "b3c.4x16.encrypted"}. Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both, an Isolated size selection and separate CPU and RAM allocation selections. Scale with the Cloud Databases API scaling endpoint, with a command like:

curl -X PATCH https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups/member
-H 'Authorization: Bearer <>'
-H 'Content-Type: application/json'
-d '{"host_flavor": {"id": "b3c.4x16.encrypted"}}' \

CPU and RAM allocation is not allowed when provisioning or scaling through Isolated Compute. Specify mulitenant for the host_flavor parameter to have independent CPU and RAM selections.

CPU and RAM autoscaling is not supported on Cloud Databases Isolated Compute. Disk autoscaling is available. If you have provisioned an Isolated instance or switched over from a deployment with autoscaling, keep an eye on your resources using IBM Cloud® Monitoring integration, which provides metrics for memory, disk space, and disk I/O utilization. To add resources to your instance, manually scale your deployment.

Review current resources and hosting model

Review resource allocations to your database by checking your terraform scripts for cpu { allocation_count = }, memory {allocation_mb = }, and disk { allocation_mb = }. Review the host_flavor setting to determine if your database is a Shared Compute or Isolated Compute style hosting model. If host_flavor does not exist, your database is on an old style hosting model.

Scaling with Terraform

Before executing a Terraform script on an existing instance, use the terraform plan command to compare the current infrastructure state with the desired state defined in your Terraform files. Any alteration to the resource_group_id, service plan, version, key_protect_instance, key_protect_key, backup_encryption_key_crn attributes recreates your instance. For a list of current argument references with the Forces new resource specification, see the ibm_database Terraform Registry.

Scale your instance by adjusting your Terraform script for the resource you're interested in. In the following example, cpu, memory, and disk allocations are specified. Note that if you have a host flavor selected (Isolated Compute or Shared Compute Multitenant), keep the host flavor selection in your script.

To implement your change, run terraform apply.

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mysql"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    cpu {
      allocation_count = 6
    }
    memory {
      allocation_mb = 24576
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MySQL database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}

Switching to and scaling hosting models in Terraform

Select the hosting model you want your database to be scaled to. You can change this later.

To scale your Databases for MySQL instance to the Shared Compute hosting flavor, set the "host_flavor" parameter to multitenant. This works if you want to scale to the Shared Compute hosting flavor, or if you want to keep the host flavor and scale your resources. To implement your change, run terraform apply.

See the following example:

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mysql"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    host_flavor {
      id = "multitenant"
    },
    cpu {
      allocation_count = 6
    }
    memory {
      allocation_mb = 24576
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MySQL database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}

Scale your Databases for MySQL instance to Isolated Compute with the same "host_flavor" parameter, set to the desired Isolated size. This command works to scale your database instance to a different Isolated Compute size, as well as to move from another host flavor to the Isolated Compute host flavor. Available hosting sizes and their host_flavor value parameters are listed in Table 1. For example, {"host_flavor": "b3c.4x16.encrypted"}. Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both an Isolated size selection and separate CPU and RAM allocation selections.

To implement your change, run terraform apply.

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mysql"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    host_flavor {
      id = "b3c.8x32.encrypted"
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MySQL database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}