When using RAID 0 in MAAS3.0, the calculated total disk size is incorrect is

disk space

total disk space shown after RAID 0

Hi there, could you please provide the output of the following:

maas $PROFILE block_devices read $MACHINE_SYSTEM_ID

This way we can see what the backend is reporting for size of each disk and the RAID 0 device.

after logging into the CLI and running the command:

$ maas admin block_devices read vm00

reports back
argument COMMAND: invalid choice: 'block_devices' (choose from 'account', 'bcache-cache-set', 'bcache-cache-sets', 'bcache', 'bcaches', 'block-device', 'block-devices', 'boot-resource', 'boot-resources', 'boot-source', 'boot-source-selection', 'boot-source-selections', 'boot-sources', 'commissioning-script', 'commissioning-scripts', 'dhcpsnippet', 'dhcpsnippets', 'dnsresource', 'dnsresource-record', 'dnsresource-records', 'dnsresources', 'device', 'devices', 'discoveries', 'discovery', 'domain', 'domains', 'events', 'fabric', 'fabrics', 'fan-network', 'fan-networks', 'file', 'files', 'ipaddresses', 'iprange', 'ipranges', 'interface', 'interfaces', 'license-key', 'license-keys', 'maas', 'machine', 'machines', 'network', 'networks', 'node-device', 'node-devices', 'node', 'node-results', 'node-script', 'node-script-result', 'node-script-results', 'node-scripts', 'nodes', 'notification', 'notifications', 'package-repositories', 'package-repository', 'partition', 'partitions', 'pod', 'pods', 'rack-controller', 'rack-controllers', 'raid', 'raids', 'region-controller', 'region-controllers', 'resource-pool', 'resource-pools', 'sshkey', 'sshkeys', 'sslkey', 'sslkeys', 'space', 'spaces', 'static-route', 'static-routes', 'subnet', 'subnets', 'tag', 'tags', 'user', 'users', 'version', 'vlan', 'vlans', 'vm-host', 'vm-hosts', 'vmfs-datastore', 'vmfs-datastores', 'volume-group', 'volume-groups', 'zone', 'zones')

virtio disk1

virtio disk 2

virtio disk 3

virtio disk 4

ubuntu@ubuntu:/var/snap/maas/common/log$ maas <profile> block-devices read nbbgm3
Success.
Machine-readable output follows:
[
    {
        "id_path": "/dev/vda",
        "size": 21474836480,
        "block_size": 512,
        "tags": [
            "ssd"
        ],
        "partitions": [],
        "path": "/dev/disk/by-dname/vda",
        "type": "physical",
        "uuid": null,
        "partition_table_type": null,
        "id": 6,
        "available_size": 21474836480,
        "name": "vda",
        "numa_node": 0,
        "model": "",
        "filesystem": null,
        "storage_pool": null,
        "used_for": "Unused",
        "used_size": 0,
        "serial": "",
        "system_id": "nbbgm3",
        "resource_uri": "/MAAS/api/2.0/nodes/nbbgm3/blockdevices/6/"
    },
    {
        "id_path": "/dev/vdb",
        "size": 10737418240,
        "block_size": 512,
        "tags": [
            "ssd"
        ],
        "partitions": [],
        "path": "/dev/disk/by-dname/vdb",
        "type": "physical",
        "uuid": null,
        "partition_table_type": null,
        "id": 7,
        "available_size": 10737418240,
        "name": "vdb",
        "numa_node": 0,
        "model": "",
        "filesystem": null,
        "storage_pool": null,
        "used_for": "Unused",
        "used_size": 0,
        "serial": "",
        "system_id": "nbbgm3",
        "resource_uri": "/MAAS/api/2.0/nodes/nbbgm3/blockdevices/7/"
    },
    {
        "id_path": "/dev/vdc",
        "size": 16535624704,
        "block_size": 512,
        "tags": [
            "ssd"
        ],
        "partitions": [],
        "path": "/dev/disk/by-dname/vdc",
        "type": "physical",
        "uuid": null,
        "partition_table_type": null,
        "id": 8,
        "available_size": 16535624704,
        "name": "vdc",
        "numa_node": 0,
        "model": "",
        "filesystem": null,
        "storage_pool": null,
        "used_for": "Unused",
        "used_size": 0,
        "serial": "",
        "system_id": "nbbgm3",
        "resource_uri": "/MAAS/api/2.0/nodes/nbbgm3/blockdevices/8/"
    },
    {
        "id_path": "/dev/vdd",
        "size": 11274289152,
        "block_size": 512,
        "tags": [
            "ssd"
        ],
        "partitions": [],
        "path": "/dev/disk/by-dname/vdd",
        "type": "physical",
        "uuid": null,
        "partition_table_type": null,
        "id": 11,
        "available_size": 11274289152,
        "name": "vdd",
        "numa_node": 0,
        "model": "",
        "filesystem": null,
        "storage_pool": null,
        "used_for": "Unused",
        "used_size": 0,
        "serial": "",
        "system_id": "nbbgm3",
        "resource_uri": "/MAAS/api/2.0/nodes/nbbgm3/blockdevices/11/"
    }
]

would be good to know if these 2 are related https://bugs.launchpad.net/maas/+bug/1938296

You can also test this by provisioning 10.00 GB partitions, and RAID 0 them together and it shows the correct total size of the RAID versus different block sizes. So, MAAS is having difficulty adding different block sizes together during a RAID setup.

Current logic in MAAS for calculating raid0 size is total_size = smallest_device_size * num_devices.

AFAICS the resulting size is actually the sum of device sizes.

Okay, Can we close this since it's working as intended. It was my misunderstanding on calculating different disk space sizes.

Actually the attached branch updates the logic in MAAS and fixes the count, as it seems that Linux RAID0 does report the sum of individual device size as available.

Is there a way to quickly check if this also resolves a related issue here? https://bugs.launchpad.net/maas/+bug/1938296

That seems a different issue, not specific to RAID