blkdiscard is a command-line utility in Linux that is used to discard (or “trim”) blocks of data from a block device, such as a hard drive or solid-state drive (SSD). Discarding blocks of data from a block device can help to improve the performance and efficiency of the device by reclaiming unused space and reducing the amount of unnecessary data that the device has to store and manage.
To use blkdiscard, you will need to have the blkdiscard utility installed on your Linux system. blkdiscard is usually included as part of the util-linux package, which is a collection of system utilities that are commonly used on Linux systems.
Once blkdiscard is installed, you can use it to discard blocks of data from a block device by running the blkdiscard command followed by the name of the device file. For example, to discard all the blocks of data from the block device /dev/sda, you could use the following command:
# blkdiscard /dev/sda
blkdiscard supports a variety of command-line options that allow you to customize the discard process, such as the range of blocks to discard or the size of the blocks to discard. You can use these options to fine-tune the discard process to suit your needs.
blkdiscard Comamnd Examples
1. Discard all sectors on a device, removing all data:
# blkdiscard /dev/device
2. Securely discard all blocks on a device, removing all data:
# blkdiscard --secure /dev/device
3. Discard the first 100 MB of a device:
# blkdiscard --length 100MB /dev/device