Support for lvm striped volume

[c4m4]

Manually, I could create one lvm striped volume, using the following lvm command:

lvcreate -i 3 -n vol -l 100%FREE vg_test

But using this role, I don't see any option to create a volume using number of stripes, I already took a look in library/blivet.py and nothing is there regarding this.

[richm]

Manually, I could create one lvm striped volume, using the following lvm command:

lvcreate -i 3 -n vol -l 100%FREE vg_test

But using this role, I don't see any option to create a volume using number of stripes, I already took a look in library/blivet.py and nothing is there regarding this.

@vojtechtrefny is there a way to do this?

[vojtechtrefny]

We are automatically setting number of stripes for striped LVs to match the number of PVs. So with a VG on top of three PVs something like

  tasks:
    - name: Create VG test
      include_role:
        name: linux-system-roles.storage
      vars:
        storage_pools:
         - name: test
           type: lvm
           volumes:
             - name: vol
               size: 1g
               raid_level: striped

will create LV with three stripes:

$ sudo lvs test -o+segtype,stripes
  LV   VG   Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Type    #Str
  vol  test -wi-a----- 1,01g                                                     striped    3

and to reduce the number of stripes you can specify the list of raid_disks to use like this

  tasks:
    - name: Create VG test
      include_role:
        name: linux-system-roles.storage
      vars:
        storage_pools:
         - name: test
           type: lvm
           volumes:
             - name: vol
               size: 1g
               raid_level: striped
               raid_disks: ["/dev/sdc", "/dev/sdd"]

to produce LV with 2 stripes

$ sudo lvs test -o+segtype,stripes
  LV   VG   Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Type    #Str
  vol  test -wi-a----- 1,00g

We currently don't support selecting the number of stripes manually.

[c4m4]

    type: lvm
    disks:
      - "/dev/sdb"
      - "/dev/sdc"
    volumes:
      - name: lv_data
        size: 100%
        fs_type: xfs
        mount_point: /mnt/data
        mount_options: defaults,noatime
        raid_level: striped
        raid_disks:
          - "/dev/sdb"
          - "/dev/sdc"

And on the ansible the execution, I have the following error: msg: 'failed to set up volume ''lv_data'': List of PVs has to be given for every non-linear LV'
Here the full ansible error output:

      - disks:
          - /dev/sdb
          - /dev/sdc
          encryption: false
          encryption_cipher: null
          encryption_key: null
          encryption_key_size: null
          encryption_luks_version: null
          encryption_password: null
          name: vg_data
          raid_chunk_size: null
          raid_device_count: null
          raid_level: null
          raid_metadata_version: null
          raid_spare_count: null
          shared: false
          state: present
          type: lvm
          volumes:
          - cache_devices: []
            cache_mode: null
            cache_size: 0
            cached: false
            compression: null
            deduplication: null
            disks: []
            encryption: false
            encryption_cipher: null
            encryption_key: null
            encryption_key_size: null
            encryption_luks_version: null
            encryption_password: null
            fs_create_options: ''
            fs_label: ''
            fs_overwrite_existing: true
            fs_type: xfs
            mount_check: 0
            mount_device_identifier: uuid
            mount_group: null
            mount_mode: null
            mount_options: defaults,noatime
            mount_passno: 0
            mount_point: /mnt/data
            mount_user: null
            name: lv_data
            raid_chunk_size: null
            raid_device_count: null
            raid_disks:
            - /dev/sdb
            - /dev/sdc
            raid_level: striped
            raid_metadata_version: null
            raid_spare_count: null
            raid_stripe_size: null
            size: 100%
            state: present
            thin: false
            thin_pool_name: null
            thin_pool_size: null
            type: lvm
            vdo_pool_size: null

[vojtechtrefny]

I hit this too when testing and actually forgot to link this issue in the PR: #536 sorry about forgetting to mention it here.
This happens when disks are used directly as PVs without partitions, setting storage_use_partitions: true should fix this for you (if you are creating the VG as well, if you already have a preexisting VG you need to wait for a new release of the role with the fix).

[c4m4]

Thanks for the advice, but using storage_use_partitions: true create partitions on my data disks, use partitions on disk that needs to be dedicated only for lvm and not OS, it's useless

[richm]

@vojtechtrefny do we need a bug fix/enhancement to address this?

[vojtechtrefny]

The bug on setups without storage_use_partitions: true was fixed in #536. @c4m4 is the automatic number of stripes with raid_level: striped and raid_disks set enough for your use case or do you need to be able to set the number of stripes manually?

[c4m4]

The bug on setups without storage_use_partitions: true was fixed in #536. @c4m4 is the automatic number of stripes with raid_level: striped and raid_disks set enough for your use case or do you need to be able to set the number of stripes manually?

Usingraid_level: striped and specifying the disks with raid_disks it's enough.

Thanks

[vojtechtrefny]

Thank you.