Linux - move ssd drive from /dev/sdb to /dev/sda and boot linux installed when the drive was mapped /dev/sdb

2 min read 24-10-2024

the ifix

Linux - move ssd drive from /dev/sdb to /dev/sda and boot linux installed when the drive was mapped /dev/sdb

When working with Linux, you might encounter situations where you need to change the device mapping of your SSD drive, particularly if you're migrating it from /dev/sdb to /dev/sda. This scenario is often seen when the drive was originally installed and configured under the /dev/sdb mapping but needs to boot under /dev/sda. Let’s dive into this process, analyze the steps involved, and ensure a seamless transition.

Understanding the Problem

The initial problem can be summarized as follows: You want to move your SSD drive from /dev/sdb to /dev/sda, enabling your Linux operating system to boot successfully using the new device mapping. Here's how we can phrase the original code you might have encountered:

sudo dd if=/dev/sdb of=/dev/sda bs=4M status=progress

This command is attempting to clone data from the SSD at /dev/sdb to /dev/sda. However, simply cloning the drive isn't sufficient for booting the operating system, as additional steps are needed.

Steps to Transition the SSD Drive

Backup Important Data: Before proceeding with any disk operations, ensure that you back up any important data on both drives. Data loss during disk operations can occur unexpectedly.
Identify Current Device Mappings: Use the following command to confirm the current mappings of your drives:
```
lsblk
```
This command will list all your block devices and their respective mappings.
Clone the Drive (if necessary): If you need to clone the drive, use the dd command carefully:
```
sudo dd if=/dev/sdb of=/dev/sda bs=4M status=progress
```
Note: Be cautious with this command as it will overwrite /dev/sda. Ensure that /dev/sda is indeed the target drive.
Update the Bootloader: After the cloning, you must update the bootloader to recognize the new device mapping:
```
sudo grub-install /dev/sda
sudo update-grub
```
Modify /etc/fstab: You may need to adjust your /etc/fstab file to point to the correct UUID of the new root filesystem. Check UUIDs with:
```
blkid
```
Then edit /etc/fstab with:
```
sudo nano /etc/fstab
```
Make sure the UUID of the root filesystem corresponds to /dev/sda.
Reboot and Test: Finally, reboot the system to check if it boots from the new device mapping:
```
sudo reboot
```

Practical Example

Let’s assume you have an SSD currently mapped to /dev/sdb that you wish to boot from /dev/sda. After following the above steps, your system should start up without issues under the new device mapping. Here’s how the procedure might play out:

You verify your SSD is /dev/sdb with lsblk.
After running the dd command, you confirm the new data on /dev/sda with lsblk.
Following that, you install and update GRUB.
Lastly, you edit /etc/fstab to ensure it matches the UUID of your new SSD.

If all is successful, your Linux operating system will boot seamlessly from the SSD now at /dev/sda.

Conclusion

Moving an SSD from /dev/sdb to /dev/sda and booting successfully requires careful planning and execution. Always ensure to backup your data and follow the steps meticulously to avoid any pitfalls.

Useful Resources

By following the outlined steps and using the provided resources, you can ensure a smooth transition of your SSD drive on Linux. Happy computing!