Disktest is a tool to check Hard Disks, Solid State Disks, USB sticks, SD cards or similar storage media for errors.
It does so by writing a pseudo random sequence to the device and then reading it back and verifying it to the expected pseudo random sequence.
This tool can be used to:
- Check disks for hardware errors (e.g. platter errors, Flash errors, etc...).
- Overwrite storage media with a cryptographically strong pseudo random stream. This can either be used to delete existing data on the disk, or to prepare the disk for encryption.
- Test for tampered media that pretend to have more storage area than they physically actually have. Sometimes such media are sold by fraudulent sellers for cheap prices.
- Measure read and write speed.
- ... probably lots of other tasks.
The random number stream is generated by the following algorithm:
OUTPUT_DATA := CHACHA20(PBKDF2(SEED | THREAD_ID))
If more than one thread is used, then each thread generates such a random number stream, which are then interleaved in a regular pattern.
The default algorithm ChaCha20 is a cryptographically strong random number generator. That means if the seed is kept secret, then the random sequence cannot be predicted or reconstructed by anybody else.
See option --seed under --help for more details.
The following disktest invocation will write a secure sequence to the disk device /dev/sdc and subsequently read back and verify the sequence from the disk device.
disktest --write --verify -j0 /dev/sdcWARNING: This will irrevocably overwrite all data on the disk /dev/sdc! Be absolutely certain that the device path is correct before starting the command. Your data cannot be recovered.
You probably need root permissions to write to raw disk devices (/dev/sdX or /dev/mmcblkX).
The target device does not have to be an actual hardware device node. It can be any file path on any file system. For example you can mount an USB stick file system and write to a file on that file system. However, please note that this leaves a couple minor untested spots in the USB stick's memory, which are reserved to the file system. Also see the Windows section below.
On Windows disktest can write to any file on any mounted storage media.
If your storage media under test is drive D, then the following command would run a write + verify test on that device:
disktest --write --verify -j0 D:\testfile.img- Rust (edition 2018) or later.
- Crate dependencies will automatically be downloaded by cargo.
Download the latest version of disktest from crates.io and install it to $HOME/.cargo/bin:
cargo install disktestBuild disktest and install it to $HOME/.cargo/bin:
cd path/to/source/package
cargo install --path .Build and run disktest in place without installing it:
cd path/to/source/package
cargo run --release -- DISKTEST_OPTIONS_HERESee below for a description of the available disktest options.
Please run either of the following commands to show more information about the available command line options.
cargo run --release -- --help
cargo run --release -- -h
disktest --help
disktest -hThe following table shows some example speed measurements of disktest in various operation mode on different hardware.
These speed tests don't write to an actual disk, but only to the /dev/null device, which is a device that does nothing. So these speed test results do not include the speed limits of any actual disk hardware.
| Command | Algorithm | Hardware | Data rate written |
|---|---|---|---|
| disktest -j4 -ACHACHA20 -w /dev/null | ChaCha20 | Intel i5-3320M; 2+2 cores 2.6 GHz | 2.0 GiB/s |
| disktest -j4 -ACHACHA12 -w /dev/null | ChaCha12 | Intel i5-3320M; 2+2 cores 2.6 GHz | 3.1 GiB/s |
| disktest -j4 -ACHACHA8 -w /dev/null | ChaCha8 | Intel i5-3320M; 2+2 cores 2.6 GHz | 4.2 GiB/s |
| disktest -j4 -ACRC -w /dev/null | CRC | Intel i5-3320M; 2+2 cores 2.6 GHz | 4.6 GiB/s |
| disktest -j6 -ACHACHA20 -w /dev/null | ChaCha20 | AMD Phenom II X6 1090T; 6 cores 3.2 GHz | 3.0 GiB/s |
| disktest -j6 -ACHACHA12 -w /dev/null | ChaCha12 | AMD Phenom II X6 1090T; 6 cores 3.2 GHz | 3.9 GiB/s |
| disktest -j6 -ACHACHA8 -w /dev/null | ChaCha8 | AMD Phenom II X6 1090T; 6 cores 3.2 GHz | 4.5 GiB/s |
| disktest -j6 -ACRC -w /dev/null | CRC | AMD Phenom II X6 1090T; 6 cores 3.2 GHz | 6.3 GiB/s |
| disktest -j4 -ACHACHA20 -w /dev/null | ChaCha20 | Raspberry Pi 4; 4 cores 1.5 GHz | 300 MiB/s |
| disktest -j4 -ACHACHA12 -w /dev/null | ChaCha12 | Raspberry Pi 4; 4 cores 1.5 GHz | 400 MiB/s |
| disktest -j4 -ACHACHA8 -w /dev/null | ChaCha8 | Raspberry Pi 4; 4 cores 1.5 GHz | 500 MiB/s |
| disktest -j4 -ACRC -w /dev/null | CRC | Raspberry Pi 4; 4 cores 1.5 GHz | 680 MiB/s |
The read data rates are similar, because the algorithm used is exactly the same.
Note: The default rust compiler shipped with Raspberry Pi OS is too old to compile Disktest. A newer Rust compiler must be used on Raspberry Pi.
Copyright (c) 2020 Michael Buesch <m@bues.ch>
Licensed under the terms of the GNU General Public License version 2, or (at your option) any later version.