# OS Disk Role

Manages LVM (Logical Volume Management) setup for Debian systems, including volume groups, logical volumes, filesystem creation, and mounting.

## What it does

This role:
- Installs LVM2 and parted packages
- Deploys a disk detection script (`setup_lvm_devices.sh`) for automatic device initialization
- Creates and manages volume groups (VGs) from physical devices
- Creates logical volumes (LVs) with specified sizes
- Formats logical volumes with filesystems
- Mounts logical volumes and adds entries to `/etc/fstab`

## Variables

### `disks_vg` (list)
List of volume group configurations.

**Structure:**
```yaml
disks_vg:
  - vg: string          # Volume group name
    state: string       # present (default) | absent
    devices_dev: list   # List of device paths (e.g., ['/dev/vda', '/dev/vdb'])
```

### `disks_lv` (list)
List of logical volume configurations.

**Structure:**
```yaml
disks_lv:
  - lv: string          # Logical volume name
    vg: string          # Volume group name (must exist in disks_vg)
    size: string        # Size with unit (e.g., '20G', '500M')
    state: string       # present (mounted) | absent (destroyed)
    fstype: string      # Filesystem type (default: ext4)
```

**Notes:**
- Mount path is automatically derived from LV name: `/{{ lv | replace('_', '/') }}`
- Example: LV name `var_lib_docker` mounts to `/var/lib/docker`

## Examples

### Basic LVM setup with single volume group
```yaml
disks_vg:
  - vg: data
    devices_dev:
      - /dev/vda
      - /dev/vdb

disks_lv:
  - lv: var_lib_docker
    vg: data
    size: 20G
    fstype: ext4
  - lv: var_log
    vg: data
    size: 5G
    fstype: xfs
```

### Multiple volume groups with different states
```yaml
disks_vg:
  - vg: data
    state: present
    devices_dev:
      - /dev/vda
  - vg: backup
    state: present
    devices_dev:
      - /dev/vdc

disks_lv:
  - lv: var_lib_docker
    vg: data
    size: 20G
    state: present
    fstype: ext4
  - lv: backup_storage
    vg: backup
    size: 100G
    state: present
    fstype: ext4
```

### Removing logical volumes
```yaml
disks_lv:
  - lv: old_data
    vg: data
    size: 10G
    state: absent  # Will unmount and destroy the LV
```