Local Static Storage Provisioner

The local static storage provisioner is NOT a dynamic storage provisioner as you would expect from a cloud provider. Instead, it simply creates PersistentVolumes for all mounts under the host_dir of the specified storage class. These storage classes are specified in the local_volume_provisioner_storage_classes nested dictionary.

Example:

local_volume_provisioner_storage_classes:
  local-storage:
    host_dir: /mnt/disks
    mount_dir: /mnt/disks
  fast-disks:
    host_dir: /mnt/fast-disks
    mount_dir: /mnt/fast-disks
    block_cleaner_command:
      - "/scripts/shred.sh"
      - "2"
    volume_mode: Filesystem
    fs_type: ext4

For each key in local_volume_provisioner_storage_classes a "storage class" with the same name is created in the entry storageClassMap of the ConfigMap local-volume-provisioner. The subkeys of each storage class in local_volume_provisioner_storage_classes are converted to camelCase and added as attributes to the storage class in the ConfigMap.

The result of the above example is:

data:
  storageClassMap: |
    local-storage:
      hostDir: /mnt/disks
      mountDir: /mnt/disks
    fast-disks:
      hostDir: /mnt/fast-disks
      mountDir:  /mnt/fast-disks
      blockCleanerCommand:
        - "/scripts/shred.sh"
        - "2"
      volumeMode: Filesystem
      fsType: ext4

Additionally, a StorageClass object (storageclasses.storage.k8s.io) is also created for each storage class:

$ kubectl get storageclasses.storage.k8s.io
NAME            PROVISIONER                    RECLAIMPOLICY
fast-disks      kubernetes.io/no-provisioner   Delete
local-storage   kubernetes.io/no-provisioner   Delete

The default StorageClass is local-storage on /mnt/disks; the rest of this documentation will use that path as an example.

Examples to create local storage volumes

Using tmpfs
```
for vol in vol1 vol2 vol3; do
  mkdir /mnt/disks/$vol
  mount -t tmpfs -o size=5G $vol /mnt/disks/$vol
done
```
The tmpfs method is not recommended for production because the mounts are not persistent and data will be deleted on reboot.
Mount physical disks
```
mkdir /mnt/disks/ssd1
mount /dev/vdb1 /mnt/disks/ssd1
```
Physical disks are recommended for production environments because it offers complete isolation in terms of I/O and capacity.
Mount unpartitioned physical devices
```
for disk in /dev/sdc /dev/sdd /dev/sde; do
  ln -s $disk /mnt/disks
done
```
This saves time of precreating filesystems. Note that your storageclass must have volume_mode set to "Filesystem" and fs_type defined. If either is not set, the disk will be added as a raw block device.
PersistentVolumes with volumeMode="Block"

Just like above, you can create PersistentVolumes with volumeMode Block by creating a symbolic link under discovery directory to the block device on the node, if you set volume_mode to "Block". This will create a volume presented into a Pod as a block device, without any filesystem on it.
File-backed sparsefile method
```
truncate /mnt/disks/disk5 --size 2G
mkfs.ext4 /mnt/disks/disk5
mkdir /mnt/disks/vol5
mount /mnt/disks/disk5 /mnt/disks/vol5
```
If you have a development environment and only one disk, this is the best way to limit the quota of persistent volumes.
Simple directories

In a development environment, using mount --bind works also, but there is no capacity management.

Usage notes

Make sure to make any mounts persist via /etc/fstab or with systemd mounts (for Flatcar Container Linux or Fedora CoreOS). Pods with persistent volume claims will not be able to start if the mounts become unavailable.

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Local Static Storage Provisioner

Examples to create local storage volumes

Usage notes

Further reading

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