# A disk's page

> Everything BeamDisk shows for one disk: its live throughput, IOPS, latency, errors and flushes, its history and latency distribution, its connection, its settings and its actions.

Click a disk in the window's sidebar, in the Overview's table or in the quick menu to open its page. The title is the disk's name, with its server and LUN under it, such as **storage.local · LUN 0**.

## The toolbar

- **The state**, as a pill (**Connected**, **Reconnecting**…). Hover over it for what it means and since when.
- **The time range** for the charts: **5 min**, **1 h**, **24 h** or **7 d**, while the disk is connected.
- **Show in Finder**, which opens the disk's volume.
- **Eject**, or **Attach** for a disk that isn't attached.
- **Options** (**…**): **Try Again** (for a disk that isn't connected), **Remount**, **Reclaim Free Space** (APFS disks), **Test Speed…**, **Erase and Reformat…**, **Connect at Login**, and **Remove…**, which needs the disk ejected first.
- **Settings** and **Add Disk**.

## When something needs you

If the disk's state has something to say, a banner at the top says it, with since when (for a problem) and the one thing to do: **Remount**, **Eject**, **Format…**, **Try Again**, **Take Over…**, **Attach Again**, **Use the New Space…** or **Attach**. [What a disk's state means](https://beamdisk.app/docs/troubleshooting/disk-states/) lists them all.

## Now

A strip across the top shows what the disk is doing, with **Live** beside the title while the numbers update:

| Figure | What it is |
|---|---|
| **Throughput** | Reads plus writes over the last second, with **Read** and **Write** beside it. |
| **IOPS** | Reads and writes per second, over the last second. |
| **Latency p50** | Half of the reads and writes in the last 5 seconds finished faster than this. Reads and writes are shown apart below it. |
| **Latency p99** | All but 1 in 100 of the reads and writes in the last 5 seconds finished faster than this. |
| **Errors** | Reads and writes that failed and were reported to apps, over the chart's time range. Anything above 0 shows in red. |
| **Flushes** | Requests to the server to save what it has received so far, per second, with the average over the time range. Apps and macOS send them to make data safe. |

## History

The chart shows one figure at a time over the time range: **Throughput**, **IOPS** or **Latency** (with **p50** or **p99**), reads and writes as two lines. Its legend shows the latest values; move the pointer over the chart to read any moment. Each point is a second at 5 min, and an average over 12 seconds, 5 minutes or 30 minutes at the longer ranges. History is kept for 7 days on this Mac.

**Latency distribution** shows how long the disk's reads and writes took over the time range, as the share of them in each band from under 64 µs to a second or more: reads above the axis, writes below it, with the p50 and p99 marked. Its title counts the reads and writes it covers. A disk whose reads cluster far to the right is waiting on its server or network: see [Get the most from your network](https://beamdisk.app/docs/performance/tuning/).

## Connection

| Row | Shows |
|---|---|
| **Server** | The server it's on. Click it for [the server's page](https://beamdisk.app/docs/using/servers/). |
| **Target** | The target's full name, with a button that copies it. |
| **LUN** | The disk's number on the target. |
| **Session** | How long it has been logged in to the server, and how many times it has reconnected since BeamDisk connected it (**Up 7 h 15 min · 1 reconnect**). Disks on one target share its session: then the row names the others (**Up 6 d 4 h · shared with Scratch**). |
| **Authentication** | **CHAP** or **None**. |
| **Digests** | Whether CRC32C checksums are in use: **CRC32C header + data**, **CRC32C header**, **CRC32C data** or **None**. |
| **New settings** | Only when a setting waits for the disk's next login to the server. **Reconnect and Apply Now** applies it now, and reconnects the disks that share its session too; if the server refuses it, the row says why, and the previous settings stay in use. |
| **Last event** | The last thing the server or the connection reported, when, and how long ago, such as **The server reported a reset or restart.** |

Under them:

- **Connect at login**: connect and attach this disk whenever BeamDisk opens; with Open at Login on, that's when you log in.
- **Power-loss protection**: **Automatic**, **On** or **Off**, with a note on what it's doing and why. See [Power-loss protection](https://beamdisk.app/docs/disks/power-loss-protection/).

At the bottom, a line repeats how long writes are held if the server stops responding.

## Disk

| Row | Shows |
|---|---|
| **Capacity** | Its size, as Finder counts it. |
| **Sector size** | 512 B or 4 KiB. |
| **Contents** | What's on it: **APFS**, **Empty**, **Formatting…**, or another file system. |
| **Access** | **Read-write**; **Read-only**, or **Read-only (4 KiB sectors)** for a disk opened read-only for that reason; or **Not shown** for a disk macOS can't read. |
| **Mounted at** | Where its volume is, while it's mounted. |

Under them:

- **Spotlight**: whether Spotlight searches this disk. See [Spotlight on a disk](https://beamdisk.app/docs/disks/spotlight/).
- **Free space on the server**, on APFS disks: when BeamDisk last gave space back and how much, and **Reclaim Free Space**. See [Give free space back to the server](https://beamdisk.app/docs/disks/free-space/).
- **Notes** about what BeamDisk found on the disk when it connected, if any, such as a damaged partition table.
- At the bottom, **Show in Finder**, **Eject** (or **Attach**, or **Format…** for an empty disk) and **Remove…**

## A disk that isn't connected

A disk that's connecting, retrying or refused shows why instead of charts: its state, since when, what happened in plain words and, under it, the technical detail. If the server doesn't allow this Mac, it shows this Mac's initiator name with a button that copies it. Then **Try Again**, **Take Over…** (for a disk another computer has) and **Remove…**, and a card, **On the server**, with where the disk is. See [A disk won't connect](https://beamdisk.app/docs/troubleshooting/wont-connect/).