# BeamDisk > BeamDisk connects a Mac with Apple Silicon to iSCSI storage on a server or SAN. The disk shows up in Finder, Disk Utility and Time Machine like a drive plugged into the Mac, reads and writes at full 10 GbE speed, over 1.2 GB/s, and needs no kernel extension or change to the Mac's security settings. It's free to download and free for home use; business use needs a license. On a Mac with Apple Silicon, an iSCSI initiator built as a kernel extension only loads after the Mac is restarted into Recovery, its security policy is lowered to Reduced Security, and the extension is approved, on every Mac. BeamDisk needs none of that: it's a sandboxed Mac App Store app that asks to be turned on once in System Settings, and the Mac's security settings stay as they are. Measured on 10 GbE (Apple M4 Mac, macOS 27): to a Linux iSCSI target with SATA SSDs, sequential reads at 1,230 MB/s and writes at 1,236 MB/s (through APFS on the disk, over 99% of what 10 GbE can carry) and 20.2K random 16 KiB reads and 24.0K random 16 KiB writes per second, each direction measured on its own and sustained over 180 seconds; with reads and writes at the same time, 1,844 MB/s in all (sequential) and 26.2K random 16 KiB operations a second at 70% reads; to a TrueNAS SSD pool, a first full Time Machine backup (71.4 GB, 1.8 million files) in 8 min 19 s, against 9 min 39 s for the same backup over SMB to the same pool. It finds a server's disks by address (SendTargets), authenticates with CHAP or mutual CHAP (secrets in the Keychain), takes exclusive access to each disk with SCSI persistent reservations so a second computer can't corrupt it, holds writes through outages of up to 60 seconds (15-300) and reconnects by itself, returns free APFS space to the server, shows live throughput and IOPS in the menu bar, and has a built-in speed test. Download BeamDisk free and use every feature for 30 days. After that, home use stays free with one server and unlimited disks on it, and a one-time $25 purchase unlocks everything, for good. Using BeamDisk for work, at a business or for paid work at home, needs Pro or BeamDisk for Business after the trial, one purchase per Mac. Made by 3rd Bit Labs LLC. **Get it.** Free, in beta on TestFlight while places last; the Mac App Store release is coming soon: https://beamdisk.app/download/ **Requirements.** A Mac with Apple Silicon on macOS 27 or later, and an iSCSI target on a storage server or SAN (tested with TrueNAS and Linux LIO). Wired Ethernet is recommended. ## Pages - [Home](https://beamdisk.app/): What BeamDisk does, benchmarks, the security story, features, compatibility, free qualification for storage vendors, pricing summary and the FAQ. - [Benchmarks](https://beamdisk.app/benchmarks/): Every benchmark run, second by second, with the rig and the method. - [Download](https://beamdisk.app/download/): Where to get BeamDisk: how to join the free TestFlight beta and what it needs, the beta's questions answered (cost, how long a build lasts, feedback, leaving it), and the Mac App Store release, coming soon. - [Pricing](https://beamdisk.app/pricing/): Free during the beta; from the release, the free trial (30 days), free home use, the one-time Pro purchase, and licensing for business use. - [For business](https://beamdisk.app/business/): Deploying BeamDisk to a fleet of Macs: security, volume purchase, licensing and data safety. - [iSCSI on a Mac with Apple Silicon](https://beamdisk.app/iscsi-on-mac/): The ways to use iSCSI storage on an Apple Silicon Mac, compared, and how to set up BeamDisk. - [Time Machine over iSCSI](https://beamdisk.app/time-machine-iscsi/): Backing up a Mac with Time Machine to an iSCSI disk on a storage server. - [Documentation](https://beamdisk.app/docs/): Install, add a disk, using the app, disks, Time Machine, storage server setup, performance, deployment, troubleshooting and every setting. - [Press kit](https://beamdisk.app/press/): For writing about BeamDisk: a one-line and a one-paragraph description, the fact sheet, what's new about it, the logo and icon files, and the press contact. - [Contact](https://beamdisk.app/contact/): The contact form, by category: support requests, storage vendors qualifying BeamDisk with their iSCSI targets (free of charge), business and licensing, feedback and ideas, press. - [Privacy policy](https://beamdisk.app/privacy/): What BeamDisk and this site collect: nothing about your storage, no account, no analytics in the app, and what the contact form sends. - [Terms of use](https://beamdisk.app/terms/): BeamDisk's licence and the site's terms: the free trial and home use, Pro and business licences (business use includes nonprofits, schools, government and paid work), your storage and data, warranties, liability, and disputes (New Mexico law and courts). ## Docs: Getting started - [Install BeamDisk](https://beamdisk.app/docs/getting-started/install/): Install BeamDisk on a Mac with Apple Silicon, turn it on in System Settings, and allow it to attach disks and use the local network. No kernel extension, no restart. - [Add your first disk](https://beamdisk.app/docs/getting-started/add-a-disk/): Connect BeamDisk to an iSCSI target on your server: enter its address and CHAP details, choose and name its disks, connect at login, and use them in Finder. - [A quick tour](https://beamdisk.app/docs/getting-started/first-look/): Where BeamDisk shows your disks: the menu-bar item and its quick menu, the window's Overview, each disk's page, and Settings, in two minutes. - [Remove BeamDisk](https://beamdisk.app/docs/getting-started/uninstall/): How to stop using BeamDisk on a Mac: stop Time Machine backups to its disks, remove the Time Machine profile, remove your disks and their CHAP secrets, and delete the app. ## Docs: Using BeamDisk - [The menu bar and the quick menu](https://beamdisk.app/docs/using/menu-bar/): BeamDisk's menu-bar item: its live throughput and IOPS readout, the amber and red badges, its tooltip, and every item in the quick menu. - [The window and the Overview](https://beamdisk.app/docs/using/overview/): BeamDisk's window: the sidebar of servers and disks, the toolbar, and the Overview's alerts, totals, five-minute to seven-day charts and table of every disk. - [A server's page](https://beamdisk.app/docs/using/servers/): Everything BeamDisk shows for one storage server: its disks' throughput and latency together, its sessions, every target and disk it offers this Mac, what's new on it, and Check for New Disks, Edit Server and Remove Server. - [A disk's page](https://beamdisk.app/docs/using/disk-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. - [Messages and notifications](https://beamdisk.app/docs/using/messages/): How BeamDisk tells you what happened and when: the latest message and its history in the window, times on every problem, alerts, and the notifications it sends when a server stops responding or a disk comes back. - [Keyboard shortcuts](https://beamdisk.app/docs/using/shortcuts/): BeamDisk's keyboard shortcuts in its window, its menus and the quick menu, and the keys its sheets answer to. ## Docs: Disks - [Format a new disk](https://beamdisk.app/docs/disks/format/): Format an empty iSCSI disk as APFS in BeamDisk, tuned for network storage or for Time Machine, erase a disk back to empty, erase and reformat it, or use Disk Utility for another format. - [Connect, eject and remove disks](https://beamdisk.app/docs/disks/connect-and-eject/): What connected and attached mean in BeamDisk, and how to connect at login, eject, attach, remount, disconnect everything, quit, and remove a disk from a Mac. - [File systems](https://beamdisk.app/docs/disks/file-systems/): Which file systems BeamDisk reads and writes on an iSCSI disk: APFS and Mac OS Extended (Journaled) read-write; exFAT, FAT and NTFS read-only; disks from Windows or Linux with 4 KiB sectors read-only; others left unattached. - [When the server stops responding](https://beamdisk.app/docs/disks/outages/): What BeamDisk does when the network drops or the server restarts: it holds writes for up to 60 seconds (15 to 300), reconnects by itself on a set schedule, shows how long it's been, and tells you. - [Power-loss protection](https://beamdisk.app/docs/disks/power-loss-protection/): BeamDisk's per-disk Power-loss protection setting: what Automatic, On and Off do, why it's on for TrueNAS, and what turning it off costs and gains. - [One Mac per disk](https://beamdisk.app/docs/disks/exclusive-access/): Why an iSCSI disk can only be used by one Mac at a time, how BeamDisk enforces it with persistent reservations, how to take a disk back from another computer, and how to move a disk to another Mac. - [Give free space back to the server](https://beamdisk.app/docs/disks/free-space/): How BeamDisk returns the space freed by deleted files on an APFS disk to a thin-provisioned volume on the server, automatically and with Reclaim Free Space. - [Make a disk bigger](https://beamdisk.app/docs/disks/grow/): Grow an iSCSI disk on your server and use the new space on the Mac with BeamDisk's Use the New Space, including the one Terminal command macOS requires, and what happens if a disk gets smaller. - [Spotlight on a disk](https://beamdisk.app/docs/disks/spotlight/): Whether Spotlight searches a BeamDisk disk: off by default, on for Time Machine disks, and how to turn it on or off for a disk, or when you format it. ## Docs: Time Machine - [Back up with Time Machine](https://beamdisk.app/docs/time-machine/set-up/): Use an iSCSI disk on your server as a Time Machine destination with BeamDisk: format an empty disk for Time Machine, install BeamDisk's Time Machine profile once in Device Management, and choose the disk. With measured backup times. ## Docs: Your storage server or SAN - [Set up TrueNAS](https://beamdisk.app/docs/targets/truenas/): Create an iSCSI target and a disk (zvol) on TrueNAS for a Mac with BeamDisk, allow the Mac's initiator name, and choose settings that work well: 16 KiB blocks, 512-byte extents, default sync and logbias, SSDs or a SLOG, and jumbo frames. - [Set up a Linux target (LIO)](https://beamdisk.app/docs/targets/linux-lio/): Serve an iSCSI disk to a Mac with BeamDisk from Linux's built-in LIO target with targetcli: a disk from a logical volume or a file, the Mac's initiator name, the folder LIO keeps reservations in, and the settings BeamDisk's benchmarks ran with on 10 GbE. - [What a target needs](https://beamdisk.app/docs/targets/requirements/): The iSCSI features BeamDisk needs from a target: SendTargets discovery, an allowed initiator name, CHAP with MD5, persistent reservations, a disk size in whole MiB or GiB, and optionally UNMAP and CRC32C digests. ## Docs: Performance - [Test Speed](https://beamdisk.app/docs/performance/test-speed/): Measure a disk's real throughput, IOPS and latency with BeamDisk's built-in Test Speed: eight tests in about a minute that read and write files as apps do, with each test's average, slowest and fastest second, and latency; test files are removed afterwards. - [Get the most from your network](https://beamdisk.app/docs/performance/tuning/): What decides BeamDisk's speed: the network and jumbo frames, the server's pool and its settings, power-loss protection, the disk's format, the Mac itself, and how apps read and write. With measured numbers on 10 GbE. ## Docs: Deploying to a fleet - [Deploy to a fleet](https://beamdisk.app/docs/deployment/fleet/): Roll BeamDisk out to Macs with Apple Silicon with Apple Business Manager and your MDM: no kernel extension to approve, one switch per Mac, and an initiator name per Mac. ## Docs: Troubleshooting - [Add Disk can't find my disks](https://beamdisk.app/docs/troubleshooting/cant-find-disks/): What to check when BeamDisk's Add Disk finds no targets or disks, and what each of its messages means: the address and port, the allowed initiator name, CHAP, and local network access. - [A disk won't connect](https://beamdisk.app/docs/troubleshooting/wont-connect/): Why a disk added to BeamDisk shows Retrying or Can't connect, what each explanation means (initiator name, CHAP, the disk's size, a missing target, another computer), and how to fix it. - [What a disk's state means](https://beamdisk.app/docs/troubleshooting/disk-states/): Every state BeamDisk shows for a disk, from Connected and Reconnecting to Reserved by another computer and Remount needed: its glyph, what it means, since when, and the one thing to do about each. - [A disk won't eject or disconnect](https://beamdisk.app/docs/troubleshooting/cant-eject/): What to do when BeamDisk can't eject a disk, or Disconnect All stops because a disk is in use: find what's using it (an open file, Spotlight or Time Machine), then try again. - [Get help](https://beamdisk.app/docs/troubleshooting/get-help/): How to reach the people who build BeamDisk, and what to include so they can help quickly: versions, your server and network, the disk's state, its last event, and BeamDisk's recent messages. ## Docs: Reference - [Settings](https://beamdisk.app/docs/reference/settings/): Every BeamDisk setting: the General, Menu Bar, Connection and Time Machine tabs, and each disk's own settings (Connect at login, Power-loss protection, Spotlight), with their defaults and when they apply. - [Compatibility](https://beamdisk.app/docs/reference/compatibility/): BeamDisk's requirements and what it's tested with: Macs with Apple Silicon on macOS 27 or later, TrueNAS targets on SSD and hard-drive pools, Linux LIO targets, CHAP, file systems, Time Machine, and what isn't in version 1. - [iSCSI terms](https://beamdisk.app/docs/reference/glossary/): The iSCSI and storage words BeamDisk and storage servers use, explained: initiator, target, LUN, IQN, portal, CHAP, discovery, persistent reservation, digest, thin provisioning, zvol, extent, sector size, SLOG, jumbo frames, IOPS, latency percentiles and flushes. - [The command-line tool](https://beamdisk.app/docs/reference/command-line/): The beamdisk command, part of BeamDisk Pro and the trial: list servers and disks with their state, connect and disconnect, attach and eject a disk, Connect at login, check a server for new disks, with JSON output and exit codes for scripts. ## Optional - [Everything in one file](https://beamdisk.app/llms-full.txt): every page of this site as markdown: the home page, the benchmarks, download, pricing, business, contact, privacy, terms, the guides and every docs page. - Markdown pages: every page has a markdown version at its address plus `index.md` (for example https://beamdisk.app/docs/getting-started/install/index.md), also sent for `Accept: text/markdown`. - [Support](https://beamdisk.app/contact/?category=support): questions answered by the people who build BeamDisk, through the contact form. - [GitHub Discussions](https://github.com/3rdBitLabs/BeamDisk/discussions): public discussion with other BeamDisk users and its makers; bugs and feature requests go in the same repository's issues. No source code.