How many physical disks required for Juju MaaS Openstack?

Hi, Openstack documentation mentions three disks (min 3x80GB) are required for the deployment of Openstack using MAAS and JUJU. This was two before. Are these physical disks or can be logical disks as well? If three physical disks are the minimum, is there any workaround for a situation where only two disks are available on the server, for example, Dell PowerEdge m620?

Thank you!

For Charmed OpenStack, the minimum number of cloud nodes is three (physical machines). Each of these nodes requires two (physical) disks; one for the host and one for a Ceph OSD. I’m basing this on the Charm Guide as documentation resource. I am not aware of any workaround for this.

@pmatulis thank you for your response.

The Openstack deployment guide using MAAS and JUJU says three disks.

Hmm yeah, that is not worded well. It says “3 x 80GiB storage”. I’ll fix that today. It should be two disks per node. One for the host’s root disk and one for a Ceph OSD.

This three-disk pattern appears in the configurations as well.

For exmple here:

  osd-devices: /dev/sda /dev/sdb /dev/sdc /dev/sdd

Hi @pmatulis !

Thank you for your reply. I’m familiar with the two-disk requirement and was surprised to see that it was changed in the documentation. Now the Requirement says:

  • 4 x cloud nodes: 8GiB RAM, 2 CPUs, 1 NIC, 2 x 80GiB storage

but at the bottom of the page is still 3 disks and later in ceph-osd conf as I showed above.

Do you have any updates (explanation) as to why this was implemented? At this moment the guide doesn’t seem to be consistent.

Thank you!

Thank you for your tenacity in this matter. There is a difference between requirements and what can actually be done, but I agree that we should stick with the requirements throughout to avoid confusion. Updates will be made soon to the table and the ceph-osd configuration.