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A disk type is a platform-provided catalog resource that defines a persistent disk performance tier. Each environment can reference a disk type via its disk_type_ref field — this determines the storage tier and per-region cost for agent VMs. Disk types are platform-managed builtins. They are immutable — you cannot create, modify, or delete them via murmur set.

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Fields

NameTypeRequiredDescription
namestringyesUnique identifier. DNS label format: [a-z][a-z0-9-]{0,62}.
descriptionstringnoHuman-readable description shown in the dashboard. Max 1024 bytes.
substratestringyesCloud provider. Values: GCP, AWS. Must match the spec arm.
specobjectyesCloud-specific disk type details. Exactly one of gce or aws.

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GCE spec fields

Set substrate: GCP and provide spec.gce:
NameTypeRequiredDescription
gce.disk_typestringyesGCE disk type identifier (e.g. pd-balanced, pd-ssd, pd-standard).
gce.regionsmapyesPer-region pricing. Keyed by region string (e.g. us-central1). Each entry is a DiskRegionConfig.

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AWS spec fields

Set substrate: AWS and provide spec.aws:
NameTypeRequiredDescription
aws.volume_typestringyesEBS volume type identifier (e.g. gp3, io2, st1).
aws.regionsmapyesPer-region pricing. Keyed by region string (e.g. us-east-1). Each entry is a DiskRegionConfig.

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DiskRegionConfig

Each entry in the regions map contains:
NameTypeRequiredDescription
cost_per_gib_monthdoubleyesStorage cost per GiB per month in USD. Must be greater than 0.

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Examples

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Listing disk types

murmur get disk-type

NAME                  SUBSTRATE  DESCRIPTION
murmur-pd-balanced    GCP        Balanced persistent disk
murmur-pd-ssd         GCP        SSD persistent disk
murmur-gp3            AWS        General purpose SSD (gp3)

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Reading a single disk type

murmur get disk-type murmur-pd-balanced

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GCP disk type shape

name: murmur-pd-balanced
description: "Balanced persistent disk"
substrate: GCP
gce:
  disk_type: pd-balanced
  regions:
    us-central1:
      cost_per_gib_month: 0.10
    us-east1:
      cost_per_gib_month: 0.10
    europe-west1:
      cost_per_gib_month: 0.11

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AWS disk type shape

name: murmur-gp3
description: "General purpose SSD (gp3)"
substrate: AWS
aws:
  volume_type: gp3
  regions:
    us-east-1:
      cost_per_gib_month: 0.08
    us-west-2:
      cost_per_gib_month: 0.08
    eu-west-1:
      cost_per_gib_month: 0.088

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Errors

CodeMeaningWhat to do
INVALID_ARGUMENTname is requiredProvide a name field.
INVALID_ARGUMENTname must match [a-z][a-z0-9-]{0,62}Use a lowercase DNS label for name.
INVALID_ARGUMENTdescription exceeds 1024 byte limitShorten the description to 1024 bytes or fewer.
INVALID_ARGUMENTsubstrate is requiredSet the substrate field to GCP or AWS.
INVALID_ARGUMENTspec is required (gce or aws)Provide a gce or aws spec block.
INVALID_ARGUMENTsubstrate must be GCP for gce specThe substrate field does not match the spec arm. Set substrate: GCP when using gce.
INVALID_ARGUMENTsubstrate must be AWS for aws specThe substrate field does not match the spec arm. Set substrate: AWS when using aws.
INVALID_ARGUMENTgce.disk_type is requiredThe GCE spec is missing disk_type.
INVALID_ARGUMENTgce.regions must be non-emptyProvide at least one region entry in the GCE spec.
INVALID_ARGUMENTgce.regions["<region>"].cost_per_gib_month must be > 0Every region entry needs a positive cost_per_gib_month.
INVALID_ARGUMENTaws.volume_type is requiredThe AWS spec is missing volume_type.
INVALID_ARGUMENTaws.regions must be non-emptyProvide at least one region entry in the AWS spec.
INVALID_ARGUMENTaws.regions["<region>"].cost_per_gib_month must be > 0Every region entry needs a positive cost_per_gib_month.
INVALID_ARGUMENTplatform disk types are reserved for builtins and cannot be written via the catalogDisk types are platform-managed. You cannot create or modify them.