> ## Documentation Index
> Fetch the complete documentation index at: https://docs.shiftlabs.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Physical Disks

> View physical disk inventory across all Ceph cluster nodes

Physical Disks provides a comprehensive view of all storage devices across your Ceph cluster nodes. This page helps you identify available disks for OSD creation, monitor disk usage, and understand why certain disks may not be usable.

## Key Concepts

<CardGroup cols={2}>
  <Card title="Physical Disk" icon="hard-drive">
    A storage device (HDD, SSD, or NVMe) attached to a cluster node that can potentially be used as an OSD.
  </Card>

  <Card title="Available" icon="circle-check">
    A disk that meets all requirements and can be used to create a new OSD.
  </Card>

  <Card title="In Use" icon="database">
    A disk that already has one or more OSDs deployed on it.
  </Card>

  <Card title="Rejected" icon="triangle-exclamation">
    A disk that cannot be used due to specific reasons (partitions, filesystem, size, etc.).
  </Card>
</CardGroup>

## Required Permissions

| Action              | Permission                             |
| ------------------- | -------------------------------------- |
| View Physical Disks | `iam:project:infrastructure:ceph:read` |

<Info>
  This page is read-only. To create OSDs from available disks, use the **OSDs** page.
</Info>

## Disk Status

| Status           | Description                                                |
| ---------------- | ---------------------------------------------------------- |
| **Available**    | Disk is clean and can be used for OSD creation             |
| **In Use (OSD)** | Disk has one or more OSDs deployed (shows OSD IDs)         |
| **Rejected**     | Disk cannot be used; hover to see rejection reasons        |
| **Unused**       | Disk is not available but has no OSDs or rejection reasons |

## Disk Types

| Type     | Icon       | Description                             |
| -------- | ---------- | --------------------------------------- |
| **HDD**  | Hard Drive | Traditional rotational hard disk drive  |
| **SSD**  | Disc       | Solid-state drive                       |
| **NVMe** | Disc       | High-performance NVMe solid-state drive |

## How to View Physical Disks

<Steps>
  <Step title="Select Cluster">
    Choose a Ceph cluster from the cluster dropdown. Only ready (bootstrapped) clusters show disk inventory.
  </Step>

  <Step title="View Statistics">
    Review the summary cards showing:

    * **Total Disks**: All physical disks across cluster nodes
    * **Available**: Disks ready for OSD creation
    * **In Use (OSD)**: Disks with active OSDs
    * **Rejected**: Disks that cannot be used
    * **HDD**: Count of rotational drives
    * **SSD/NVMe**: Count of solid-state drives
  </Step>

  <Step title="Browse Disk List">
    The table shows all disks with device path, host, type, size, model, and status.
  </Step>

  <Step title="Filter and Search">
    Use filters to focus on specific disk states:

    * **Available**: Show only disks ready for use
    * **In Use (OSD)**: Show only disks with OSDs
    * **Rejected**: Show only unusable disks

    Search by device path, hostname, device ID, or model name.
  </Step>

  <Step title="View Rejection Reasons">
    For rejected disks, hover over the status badge to see why the disk cannot be used.
  </Step>
</Steps>

## Disk Table Fields

| Field      | Description                                  |
| ---------- | -------------------------------------------- |
| **Device** | Device path (e.g., `/dev/sda`) and device ID |
| **Host**   | Node where the disk is located               |
| **Type**   | Disk type: HDD, SSD, or NVMe                 |
| **Size**   | Total disk capacity                          |
| **Model**  | Disk model name and vendor                   |
| **Status** | Current status with details                  |

## Understanding Disk Status

### Available Disks

Available disks meet all requirements for OSD creation:

* No existing partitions or filesystems
* Sufficient size (typically > 5GB)
* Not mounted or in use
* Properly detected by the system

<Tip>
  Use the **OSDs** page to create new OSDs from available disks. Available disks appear in the Add OSD drawer.
</Tip>

### In Use (OSD) Disks

Disks with OSD status show which OSD IDs are using them:

* Single OSD per disk is typical
* Multiple OSDs may exist on large disks (with partitioning)
* The OSD ID links the disk to the OSD configuration

### Rejected Disks

Rejected disks have one or more reasons preventing OSD creation. Common rejection reasons include:

| Reason             | Description                                  |
| ------------------ | -------------------------------------------- |
| **Has partitions** | Disk has existing partition table            |
| **Has filesystem** | Disk has a filesystem (ext4, xfs, etc.)      |
| **Too small**      | Disk is below minimum size requirement       |
| **Locked**         | Disk is locked by another process            |
| **Has holders**    | Other devices depend on this disk (dm, raid) |
| **Mounted**        | Disk or partition is currently mounted       |

<Info>
  To make a rejected disk available, you must resolve the rejection reasons. This typically involves removing partitions, filesystems, or unmounting the disk.
</Info>

## Statistics Cards

### Total Disks

The total count of all physical disks detected across all cluster nodes.

### Available

Disks that are clean and ready for OSD creation. These appear in the Add OSD list on the OSDs page.

### In Use (OSD)

Disks that already have Ceph OSDs deployed. Each disk shows its associated OSD ID(s).

### Rejected

Disks that cannot be used for OSD creation due to existing data, partitions, or other restrictions.

### HDD

Count of rotational (spinning) hard disk drives. HDDs are identified by the `rotational` property.

### SSD/NVMe

Count of solid-state drives including both SATA SSDs and NVMe drives. These offer faster I/O than HDDs.

## Troubleshooting

<AccordionGroup>
  <Accordion title="No disks showing in the inventory">
    * Verify the cluster is bootstrapped and ready
    * Check that nodes have the OSD role assigned
    * Ensure disks are properly connected and detected by the OS
    * Try refreshing the inventory
  </Accordion>

  <Accordion title="Disk shows as rejected">
    * Hover over the Rejected badge to see specific reasons
    * Common causes: existing partitions, filesystems, or mounts
    * Use `lsblk` on the node to inspect the disk
    * Clean the disk with `wipefs` or `dd` if appropriate
  </Accordion>

  <Accordion title="Available disk not appearing in Add OSD">
    * Refresh both the Physical Disks and OSDs pages
    * Verify the disk shows as Available (not just Unused)
    * Check that the host has the OSD role in the cluster
    * Ensure no other process is using the disk
  </Accordion>

  <Accordion title="Disk shows wrong type (HDD vs SSD)">
    * Disk type is detected from system properties
    * Virtual disks may not report type correctly
    * Check `/sys/block/<device>/queue/rotational` on the node
    * Type detection depends on disk firmware reporting
  </Accordion>

  <Accordion title="Disk size shows as 0 or incorrect">
    * Disk may not be properly initialized
    * Check disk health with `smartctl`
    * Verify disk is detected in `lsblk` output
    * Some virtual disks report size differently
  </Accordion>

  <Accordion title="Disk missing from inventory after adding OSD">
    * After OSD creation, the disk status changes to "In Use"
    * Refresh the page to see updated status
    * The disk will show the OSD ID in its status
  </Accordion>
</AccordionGroup>

## FAQ

<AccordionGroup>
  <Accordion title="What makes a disk 'available'?">
    A disk is available when it:

    * Has no partition table
    * Has no filesystem
    * Is not mounted
    * Meets minimum size requirements
    * Is not used by LVM, RAID, or other device mappers
    * Is not locked by another process
  </Accordion>

  <Accordion title="How do I make a rejected disk available?">
    To prepare a rejected disk:

    1. Identify the rejection reason by hovering over the status
    2. Unmount any mounted partitions
    3. Remove partitions with `fdisk` or `parted`
    4. Wipe filesystem signatures with `wipefs -a /dev/sdX`
    5. Refresh the inventory to see updated status

    <Warning>
      Wiping a disk destroys all data. Ensure you have backups before proceeding.
    </Warning>
  </Accordion>

  <Accordion title="Can I use a disk that has existing data?">
    No. Ceph requires clean disks for OSD creation. You must remove all data, partitions, and filesystems before using a disk. This ensures data integrity and allows Ceph to manage the entire disk.
  </Accordion>

  <Accordion title="Why do some disks show as 'Unused' instead of 'Available'?">
    Unused status means the disk:

    * Is not available for OSD creation
    * Does not have an OSD deployed
    * Has no specific rejection reasons

    This can happen with system disks, boot devices, or disks reserved for other purposes.
  </Accordion>

  <Accordion title="How is disk type (HDD/SSD/NVMe) determined?">
    Disk type is detected from:

    * The `rotational` flag in `/sys/block/<device>/queue/rotational`
    * Device naming patterns (nvme\* for NVMe)
    * SMART data and device identification

    HDD: rotational = 1, SSD: rotational = 0, NVMe: device path starts with nvme
  </Accordion>

  <Accordion title="Can multiple OSDs use the same physical disk?">
    While technically possible through partitioning, it's not recommended:

    * Modern best practice is one OSD per physical disk
    * Multiple OSDs per disk was common with older small disks
    * Single OSD per disk provides better failure isolation
    * Ceph orchestrator typically creates one OSD per disk
  </Accordion>

  <Accordion title="What is the minimum disk size for an OSD?">
    The minimum depends on your Ceph version and configuration:

    * Default minimum is typically 5GB
    * Production systems should use much larger disks
    * Very small disks are often rejected automatically
    * Check your Ceph configuration for specific limits
  </Accordion>

  <Accordion title="Why doesn't the inventory show all disks on a node?">
    Some disks may be excluded:

    * System/boot disks are typically filtered out
    * Disks without proper block device entries
    * Removable media may be excluded
    * Disks in certain device mapper configurations

    Check `lsblk` on the node to see all block devices.
  </Accordion>

  <Accordion title="How often is the disk inventory updated?">
    The inventory is fetched from the Ceph Dashboard API when you:

    * Load or refresh the Physical Disks page
    * Add or remove OSDs
    * The underlying Ceph inventory updates periodically

    Use the refresh button to get the latest inventory data.
  </Accordion>
</AccordionGroup>