# Format a new disk

> Format an empty iSCSI disk as APFS in BeamDisk with a format tuned for network storage, erase and reformat a disk, or use Disk Utility for another format.

A new disk from your server is empty, and its state reads **Empty disk**. BeamDisk can format it as APFS, with a format tuned for disks on a storage server: random writes run up to about three times faster than on Disk Utility's standard format.

## Format an empty disk

1. Click **Format…**: it's beside the disk in the Overview's table, at the top of the disk's page, and in Add Disk's last step.
2. To have Spotlight search the disk, check **Let Spotlight search this disk**. It's off unless you do: see [Spotlight on a disk](https://beamdisk.app/docs/disks/spotlight/).
3. Click **Format**. The disk reads **Formatting…** for a moment, then appears in Finder.

The volume takes the disk's name; rename it in Finder if you like. Before attaching the new volume, BeamDisk gives the old contents' space back to the server.

## Another format

For anything else, such as Mac OS Extended or exFAT, click **Use Disk Utility…** in the Format sheet. For an empty disk, BeamDisk attaches it and opens Disk Utility: select the new disk and click **Erase**. See [File systems](https://beamdisk.app/docs/disks/file-systems/) for what each format can do with BeamDisk.

> **BeamDisk's format or Disk Utility's?**
>
> In tests, random writes ran up to about three times faster on BeamDisk's format than on Disk Utility's standard APFS format, where their speed depends on where macOS places each file. Copying files in Finder took the same time on both. The trade-off is space: a folder of many small files takes more room on BeamDisk's format.

## Erase and reformat a disk

**Erase and Reformat…**, in a disk's Options menu, erases everything on the disk and formats it again the same way.

1. Quit the apps using the disk. BeamDisk ejects it first.
2. Choose **Erase and Reformat…** from the disk's Options menu.
3. Read the warning: **Everything on Projects is erased, on the server too. This can't be undone.** If the disk holds Time Machine backups, it says so, and that Time Machine has to be set up for it again.
4. Type the disk's name to confirm, then click **Erase and Format**.

Erase and Reformat… is dimmed while a disk isn't connected, and for any disk BeamDisk opens read-only, such as exFAT, FAT or NTFS, or one written with 4 KiB sectors by another system: BeamDisk can't erase those. To reuse one, make a new disk on the server, or erase it from another computer that can write to it. Disks that macOS can't read (Linux or ZFS file systems, for example) show **Unreadable here** and are never attached, so they can't be erased by mistake. See [File systems](https://beamdisk.app/docs/disks/file-systems/).