--- layout: docs page_title: 'Commands: volume create' description: | Create volumes with CSI plugins. --- # Command: volume create The `volume create` command creates external storage volumes with Nomad's [Container Storage Interface (CSI)][csi] support. Only CSI plugins that implement the [Controller][csi_plugins_internals] interface support this command. The volume will also be [registered] when it is successfully created. ## Usage ```plaintext nomad volume create [options] [file] ``` The `volume create` command requires a single argument, specifying the path to a file containing a valid [volume specification][volume_specification]. This file will be read and the volume will be submitted to Nomad for scheduling. If the supplied path is "-", the volume file is read from STDIN. Otherwise it is read from the file at the supplied path. When ACLs are enabled, this command requires a token with the `csi-write-volume` capability for the volume's namespace. ## General Options @include 'general_options.mdx' ## Volume Specification The file may be provided as either HCL or JSON. An example HCL configuration: ```hcl id = "ebs_prod_db1" name = "database" type = "csi" plugin_id = "ebs-prod" snapshot_id = "snap-12345" # or clone_id, see below capacity_max = "200G" capacity_min = "100G" capability { access_mode = "single-node-reader-only" attachment_mode = "file-system" } capability { access_mode = "single-node-writer" attachment_mode = "file-system" } mount_options { fs_type = "ext4" mount_flags = ["noatime"] } topology_request { required { topology { segments { "rack" = "R2" } } topology { segments { "rack" = "R1", "zone" = "us-east-1a"} } } preferred { topology { segments { "rack" = "R1", "zone" = "us-east-1a"} } } } secrets { example_secret = "xyzzy" } parameters { skuname = "Premium_LRS" } ``` ## Volume Specification Parameters - `id` `(string: )` - The unique ID of the volume. This is how the [`volume.source`][csi_volume_source] field in a job specification will refer to the volume. - `name` `(string: )` - The display name of the volume. This field may be used by the external storage provider to tag the volume. - `type` `(string: )` - The type of volume. Currently only `"csi"` is supported. - `plugin_id` `(string: )` - The ID of the [CSI plugin][csi_plugin] that manages this volume. - `snapshot_id` `(string: )` - If the storage provider supports snapshots, the external ID of the snapshot to restore when creating this volume. If omitted, the volume will be created from scratch. The `snapshot_id` cannot be set if the `clone_id` field is set. - `clone_id` `(string: )` - If the storage provider supports cloning, the external ID of the volume to clone when creating this volume. If omitted, the volume will be created from scratch. The `clone_id` cannot be set if the `snapshot_id` field is set. - `capacity_min` `(string: )` - Option for setting the capacity. The volume must be at least this large, in bytes. The storage provider may return a volume that is larger than this value. Accepts human-friendly suffixes such as `"100GiB"`. This field may not be supported by all storage providers. - `capacity_max` `(string: )` - Option for setting the capacity. The volume must be no more than this large, in bytes. The storage provider may return a volume that is smaller than this value. Accepts human-friendly suffixes such as `"100GiB"`. This field may not be supported by all storage providers. - `capability` `(Capability: )` - Option for validating the capability of a volume. You must provide at least one `capability` block, and you must provide a block for each capability you intend to use in a job's [`volume`] block. Each `capability` block must have the following fields: - `access_mode` `(string: )` - Defines whether a volume should be available concurrently. Can be one of `"single-node-reader-only"`, `"single-node-writer"`, `"multi-node-reader-only"`, `"multi-node-single-writer"`, or `"multi-node-multi-writer"`. Most CSI plugins support only single-node modes. Consult the documentation of the storage provider and CSI plugin. - `attachment_mode` `(string: )` - The storage API that will be used by the volume. Most storage providers will support `"file-system"`, to mount volumes using the CSI filesystem API. Some storage providers will support `"block-device"`, which will mount the volume with the CSI block device API within the container. - `mount_options` - Options for mounting `file-system` volumes that don't already have a pre-formatted file system. This block will be validated during volume creation against the `capability` field. The `mount_options` provided in a job specification's [`volume`] block will override this block. Consult the documentation for your storage provider and CSI plugin as to whether these options are required or necessary. - `fs_type` `(string )` - File system type (ex. `"ext4"`) - `mount_flags` `([]string: )` - The flags passed to `mount` (ex. `["ro", "noatime"]`) - `topology_request` ([TopologyRequest](#topology_request-parameters): nil) - Specify locations (region, zone, rack, etc.) where the provisioned volume must be accessible from. Consult the documentation for your storage provider and CSI plugin as to whether it supports defining topology and what values it expects for topology segments. Specifying topology segments that aren't supported by the storage provider may return an error or may be silently removed by the plugin. - `secrets` (map:nil) - An optional key-value map of strings used as credentials for publishing and unpublishing volumes. - `parameters` (map:nil) - An optional key-value map of strings passed directly to the CSI plugin to configure the volume. The details of these parameters are specific to each storage provider, so please see the specific plugin documentation for more information. ### `topology_request` Parameters For the `topology_request` field, you may specify a list of either `required` or `preferred` topologies (or both). The `required` topologies indicate that the volume must be created in a location accessible from at least one of the listed topologies. The `preferred` topologies indicate that you would prefer the storage provider to create the volume in one of the provided topologies. Each topology listed has a single field: - `segments` `(map[string]string)` - A map of location types to their values. The specific fields required are defined by the CSI plugin. For example, a plugin might require defining both a rack and a zone: `segments {rack = "R2", zone = "us-east-1a"}`. For example: ```hcl topology_request { required { topology { segments { "rack" = "R1", "zone" = "us-east-1a" } } topology { segments { "rack" = "R2", "zone" = "us-east-1a" } } } preferred { topology { segments { "rack" = "R1", "zone" = "us-east-1a"} } } } ``` This configuration indicates you require the volume to be created within racks `R1` or `R2`, but that you prefer the volume to be created within `R1`. ### Unused Fields Note that several fields used in the [`volume register`] command are set automatically by the plugin when `volume create` is successful. You should not set the `external_id` or `context` fields described on that page. [csi]: https://github.com/container-storage-interface/spec [csi_plugins_internals]: /docs/internals/plugins/csi#csi-plugins [volume_specification]: #volume-specification [csi_plugin]: /docs/job-specification/csi_plugin [csi_volume_source]: /docs/job-specification/volume#source [registered]: /docs/commands/volume/register [`volume register`]: /docs/commands/volume/register [`volume`]: /docs/job-specification/volume