How to Disable UAS for USB Without Knowing Prior Device ID in GRUB

USB devices are widely used in today's technology-driven world. They allow us to connect various peripherals to our computers, from keyboards and mice to external storage devices and printers. However, sometimes these USB devices may cause issues, such as slow performance or compatibility problems. One potential solution to these problems is disabling the USB Attached SCSI (UAS) feature in the GRUB bootloader. In this article, we will guide you through the process of disabling UAS for USB without knowing the prior device ID in GRUB.

What is UAS?

UAS stands for USB Attached SCSI, which is a protocol used by USB devices to communicate with the computer. It provides faster data transfer rates and improved performance compared to the traditional USB Mass Storage protocol. However, some USB devices may not work properly with UAS, leading to compatibility issues.

Why disable UAS?

Disabling UAS for USB devices can help resolve compatibility problems and improve performance. It forces the USB device to use the older USB Mass Storage protocol, which is more widely supported by operating systems and drivers.

Disabling UAS in GRUB

Here are the steps to disable UAS for USB devices in GRUB:

1. Start by booting your computer and accessing the GRUB bootloader. If you have a dual-boot system, you may need to press a specific key (such as F12 or Esc) during startup to access the bootloader menu. If you are unsure, consult your computer's documentation or search online for the specific key for your system.
2. Once you are in the GRUB bootloader menu, use the arrow keys to highlight the desired operating system or kernel version. Do not press Enter to boot into the selected option just yet.
3. Press the 'e' key on your keyboard to edit the GRUB boot entry. This will open a text editor where you can make changes to the boot parameters.
4. Navigate to the line that starts with 'linux' or 'linuxefi' (depending on your system) and look for the section that contains the 'quiet' and 'splash' parameters.
5. At the end of this section, add the following parameter: usb-storage.quirks=vendor:product:u. Replace 'vendor' and 'product' with the vendor and product IDs of your USB device. If you do not know the IDs, you can skip this step and disable UAS for all USB devices.
6. Press Ctrl + X or F10 to boot into the modified GRUB entry and start your operating system.

Checking if UAS is disabled

After booting into your operating system, you can check if UAS is disabled for your USB devices by following these steps:

1. Open a terminal or command prompt.
2. Type the following command and press Enter: lsusb -t
3. Look for your USB device in the list. If it shows 'usb-storage' instead of 'uas', it means UAS is disabled for that device.

Conclusion

Disabling UAS for USB devices in GRUB can help resolve compatibility issues and improve performance. By following the steps outlined in this article, you can easily disable UAS even without knowing the prior device ID. However, keep in mind that disabling UAS may not be necessary for all USB devices, so it's recommended to test your device's performance before making any changes.