The Kernels & Files Datastore

The Files Datastore lets you store plain files to be used as VM kernels, ramdisks or context files. The Files Datastore does not expose any special storage mechanism but a simple and secure way to use files within VM templates. There is a Files Datastore (datastore ID: 2) ready to be used in OpenNebula.

Requirements

There are no special requirements or software dependencies to use the Files Datastore. The recommended drivers make use of standard filesystem utils (cp, ln, mv, tar, mkfs…) that should be installed in your system.

Configuration

Most of the configuration considerations used for disk images datastores do apply to the Files Datastore (e.g. driver setup, cluster assignment, datastore management…).

The specific attributes for this datastore driver are listed in the following table, you will also need to complete with the common datastore attributes:

Attribute	Description
TYPE	Use FILE_DS to setup a Files datastore
DS_MAD	The DS type, use fs to use the file-based drivers
TM_MAD	Transfer drivers for the datastore, use ssh to transfer the files

For example, the following illustrates the creation of File Datastore.

> cat kernels_ds.conf
NAME = kernels
DS_MAD = fs
TM_MAD = ssh
TYPE = FILE_DS
SAFE_DIRS = /var/tmp/files

> onedatastore create kernels_ds.conf
ID: 100

> onedatastore list
  ID NAME                      CLUSTER         IMAGES TYPE DS       TM
   0 system                    -                    0 sys  -        dummy
   1 default                   -                    0 img  dummy    dummy
   2 files                     -                    0 fil  fs       ssh
 100 kernels                   -                    0 fil  fs       ssh

The DS and TM MAD can be changed later using the onedatastore update command. You can check more details of the datastore by issuing the onedatastore show command.

Host Configuration

The recommended ssh driver for the File Datastore does not need any special configuration for the hosts. Just make sure that there is enough space under $DATASTORE_LOCATION to hold the VM files in the front-end and hosts.

For more details refer to the Filesystem Datastore guide, as the same configuration guidelines applies.