BCache: Tutorial & Best Practices

Tool to add cache to devices

Bcache is a Linux kernel feature that allows you to use a faster device, such as an SSD, as a cache for a slower device, such as a hard drive. This can improve the performance of your system by allowing frequently accessed data to be stored on the faster device, while less frequently accessed data is stored on the slower device.

To install and configure bcache on a Linux system, follow these steps:

  • Make sure that the bcache module is available on your system. On most Linux distributions, the bcache module is included in the kernel by default. If it is not, you can try to install it by running the following command:

    sudo modprobe bcache
    

    If this command fails, you may need to recompile your kernel with the bcache module enabled. Consult the documentation for your Linux distribution for more information.

  • Determine the device names of the devices you want to use as the cache and the backing device. You can use the lsblk command to list the available block devices on your system:

    lsblk
    
  • Create a bcache device using the make-bcache command. For example, to create a bcache device using /dev/sdb as the cache and /dev/sdc as the backing device, you would run the following command:

    sudo make-bcache -B /dev/sdc -C /dev/sdb
    

    This will create a new bcache device, /dev/bcache0, which you can use like any other block device.

  • Format the bcache device with a filesystem, such as ext4. For example:

    sudo mkfs.ext4 /dev/bcache0
    
  • Create a mount point for the bcache device and mount it. For example:

    sudo mkdir /mnt/bcache
    sudo mount /dev/bcache0 /mnt/bcache
    
  • Add an entry for the bcache device to the /etc/fstab file to make it persistent across reboots. For example:

    /dev/bcache0 /mnt/bcache ext4 defaults 0 0
    

Note that the above steps are just an example of how to install and configure bcache. The specific steps and configuration options may vary depending on your Linux distribution and the devices you are using. Consult the documentation for bcache and the relevant file system for more information.

make-bcache -C /dev/sdc1 -B /dev/sdb4 --discard --writeback
wipefs -a /dev/***
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