Directory - dir
Description: The directory storage driver is a basic backend that stores its data in a standard file and directory structure. This driver is quick to set up and allows inspecting the files directly on the disk,...

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# Directory - `dir`

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The directory storage driver is a basic backend that stores its data in a standard file and directory structure. This driver is quick to set up and allows inspecting the files directly on the disk, which can be convenient for testing. However, LXD operations are not optimized for this driver.

## `dir` driver in LXD

The `dir` driver in LXD is fully functional and provides the same set of features as other drivers. However, it is much slower than all the other drivers because it must unpack images and do instant copies of instances, snapshots and images.

Unless specified differently during creation (with the `source` configuration option), the data is stored in the `/var/snap/lxd/common/lxd/storage-pools/` (for snap installations) or `/var/lib/lxd/storage-pools/` directory.

### Quotas

The `dir` driver supports storage quotas when running on either ext4 or XFS with project quotas enabled at the file system level.

## Configuration options

The following configuration options are available for storage pools that use the `dir` driver and for storage volumes in these pools.

### Storage pool configuration

`rsync.bwlimit`

Upper limit on the socket I/O for `rsync`

Key: | `rsync.bwlimit`
Type: | string
Default: | `0` (no limit)

When `rsync` must be used to transfer storage entities, this option specifies the upper limit to be placed on the socket I/O.

`rsync.compression`

Whether to use compression while migrating storage pools

Key: | `rsync.compression`
Type: | bool
Default: | `true`

`source`

Path to an existing directory

Key: | `source`
Type: | string

Tip

In addition to these configurations, you can also set default values for the storage volume configurations. See Configure default values for storage volumes.

### Storage volume configuration

`security.shifted`

Enable ID shifting overlay

Key: | `security.shifted`
Type: | bool
Default: | same as `volume.security.shifted` or `false`
Condition: | custom volume

Enabling this option allows attaching the volume to multiple isolated instances.

`security.unmapped`

Disable ID mapping for the volume

Key: | `security.unmapped`
Type: | bool
Default: | same as `volume.security.unmappped` or `false`
Condition: | custom volume

`size`

Size/quota of the storage volume

Key: | `size`
Type: | string
Default: | same as `volume.size`
Condition: | appropriate driver

`snapshots.expiry`

When snapshots are to be deleted

Key: | `snapshots.expiry`
Type: | string
Default: | same as `volume.snapshots.expiry`
Condition: | custom volume

Specify an expression like `1M 2H 3d 4w 5m 6y`.

`snapshots.pattern`

Template for the snapshot name

Key: | `snapshots.pattern`
Type: | string
Default: | same as `volume.snapshots.pattern` or `snap%d`
Condition: | custom volume

You can specify a naming template that is used for scheduled snapshots and unnamed snapshots.

The `snapshots.pattern` option takes a Pongo2 template string to format the snapshot name.

To add a time stamp to the snapshot name, use the Pongo2 context variable `creation_date`. Make sure to format the date in your template string to avoid forbidden characters in the snapshot name. For example, set `snapshots.pattern` to `{{ creation_date|date:'2006-01-02_15-04-05' }}` to name the snapshots after their time of creation, down to the precision of a second.

Another way to avoid name collisions is to use the placeholder `%d` in the pattern. For the first snapshot, the placeholder is replaced with `0`. For subsequent snapshots, the existing snapshot names are taken into account to find the highest number at the placeholder’s position. This number is then incremented by one for the new name.

`snapshots.schedule`

Schedule for automatic volume snapshots

Key: | `snapshots.schedule`
Type: | string
Default: | same as `snapshots.schedule`
Condition: | custom volume

Specify either a cron expression (`<minute> <hour> <dom> <month> <dow>`), a comma-separated list of schedule aliases (`@hourly`, `@daily`, `@midnight`, `@weekly`, `@monthly`, `@annually`, `@yearly`), or leave empty to disable automatic snapshots (the default).

`volatile.uuid`

The volume’s UUID

Key: | `volatile.uuid`
Type: | string
Default: | random UUID

### Storage bucket configuration

To enable storage buckets for local storage pool drivers and allow applications to access the buckets via the S3 protocol, you must configure the `core.storage_buckets_address` server setting.

Storage buckets do not have any configuration for `dir` pools. Unlike the other storage pool drivers, the `dir` driver does not support bucket quotas via the `size` setting.