Physical disks not detected to create a datastore on OpenNebula CE 7 (Rocky Linux 9)

Product Support Installation & Configuration
1

Hello everyone,

I am new to OpenNebula. I am having a problem with OpenNebula CE 7 on Rocky Linux 9.
I want to use my server’s local physical disks as datastores, but they do not appear in the WebUI when creating a new datastore.

The disks are detected at the system level (lsblk displays them correctly).

They are not mounted or used by other services.

I would like to use them to store images/VMs directly.

My question:
:backhand_index_pointing_right: What is the correct procedure for these physical disks to be recognised by OpenNebula and available when creating a datastore (e.g. fs or ceph or other)?
Do I need to mount them manually in a specific directory or modify a configuration file for them to appear?

Thank you in advance for your help!

2

Hello,

As far as you want to use them as local datastores, you should

  • format the disk/s as a POSIX filesystem
  • create the datastore
  • mount the filesystem on the datastore directory (i.e. /var/lib/one/datastores/100)

We would like you to know that there are three kind of datastores (FILE, IMAGE and SYSTEM):

  • FILE is used to store files that may be copied to the VMs. Normally is only in the frontend, which copies the necessary things to VMs via contextualization
  • IMAGE filesystems store the “golden images” for each VM. Normally they are stored as well in the frontend. This images are copied to the hypervisors when they are needed
  • SYSTEM stores running VM disks (as well as their snapshots). They have to exist on every hypervisor. As this will be a local filesystem on a local disk, when a VM is moved to another hypervisor this data will be copied as well

If you need more information, please, check the documentation about the local datastores

Thank you!

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3

Hello,

Thank you for your detailed response and clear explanations regarding the configuration of local databases in OpenNebula.

Your clarifications on the different types of datastores (FILE, IMAGE, and SYSTEM) and their respective roles were particularly helpful.

I will follow your recommendations regarding the formatting, mounting and creation of datastores, and consult the documentation to learn more about the subject.

Kind regards,

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