Linux command
blkdiscard 命令
文本
复制后可按需替换文件名、目录或参数。
常用示例
Discard
blkdiscard /dev/device
Secure
blkdiscard -s /dev/device
Example
blkdiscard -l 100M /dev/device
Example
blkdiscard -p 512M /dev/device
说明
blkdiscard sends TRIM/DISCARD commands to a block device to mark sectors as unused. Unlike fstrim(8), it operates directly on the block device rather than a mounted filesystem. This is particularly useful for SSDs and thinly-provisioned storage. All data in the discarded region will be lost.
参数
- -o, --offset _offset_
- Byte offset into the device to start discarding. Must be aligned to the device sector size. Default is 0.
- -l, --length _size_
- Number of bytes to discard from the offset. Must be aligned to the device sector size.
- -p, --step _size_
- Discard this many bytes per iteration instead of all at once. Useful for avoiding long uninterruptible operations on large devices.
- -s, --secure
- Perform a secure discard. This tells the device to also erase any copies of the discarded data (e.g. in garbage collection). Requires device support.
- -z, --zeroout
- Zero-fill the specified region rather than discarding it.
- -f, --force
- Disable exclusive-open check, allowing operation on mounted devices. Use with caution.
- -q, --quiet
- Suppress warning messages.
- -v, --verbose
- Print aligned offset and length values and progress information.
FAQ
What is the blkdiscard command used for?
blkdiscard sends TRIM/DISCARD commands to a block device to mark sectors as unused. Unlike fstrim(8), it operates directly on the block device rather than a mounted filesystem. This is particularly useful for SSDs and thinly-provisioned storage. All data in the discarded region will be lost.
How do I run a basic blkdiscard example?
Run `blkdiscard /dev/device` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -o, --offset _offset_ do in blkdiscard?
Byte offset into the device to start discarding. Must be aligned to the device sector size. Default is 0.