如何使用Python获取Windows中的原始磁盘或块设备大小

Question

如果我只知道设备名是“\.\PhysicalDrive0”，但没有文件系统或卷标，如何从Windows的块设备或原始磁盘获取大小？在

我尝试了以下方法：

fd = os.open(r"\.\PhysicalDrive0", os.O_RDONLY)

os.lseek(fd, 0, os.SEEK_END)

它在Linux上运行良好，但在Windows上总是返回“OSError:[Errno 22]Invalid argument”。在

我也试过ctypes.windll.kernel32.GetDiskFreeSpaceExW（），但它似乎仅适用于具有文件系统和分配了卷标的磁盘。在

对于原始磁盘或块设备，正确的方法是什么？在

提前谢谢。在

Answer 1

我有个解决办法。。但不漂亮。使用diskpart。不幸的是，如果需要的话，它没有给您一个精确的字节大小，但是它提供了一个人类可读的字符串。在

import tempfile
import subprocess
import re
import os

def query_diskpart(command):
    """Run command script for diskpart.

    Args:
        command(str): String of all commands to run against diskpart
    Returns:
        String of all diskpart standard output
    Size Effects:
        Creates a temporary file(and then deletes it)
        Creates a subprocess to run diskpart
    """
    with tempfile.NamedTemporaryFile(mode='w', delete=False) as temp_handle:
        temp_handle.write(command)
    # The temporary file needs to be closed before opening with diskpart
    diskpart_handle = subprocess.Popen(["diskpart", '/s', temp_handle.name], stdout=subprocess.PIPE)
    output, _ = diskpart_handle.communicate()

    os.remove(temp_handle.name)
    return output

def match_drive_size(diskpart_output, disk_num):
    """Get drive size from diskpart output.

    Args:
        diskpart_output(str): String of diskpart standard output
        disk_num(int): Number of PhysicalDrive to match against
    Returns:
        Human readable size of drive.
    Raises:
        ValueError if drive doesn't exist.
        """

    # Break up gigantic output string
    output_lines = diskpart_output.decode().split(os.linesep)
    # Apply regular expression to every line, but it should only match one
    matches = [re.match(".*Disk %s\s*(.*)" % disk_num, line) for line in output_lines]
    size = None
    for match in matches:
        if match:
            # Get first subgroup (parens above)
            size_line = match.group(1)
            # Split by whitespace
            size_list = re.split("\s*", size_line)
            # Merge numerical value + units
            # ['256', 'GB'] becomes 256GB
            size = ''.join(size_list[1:3])
            break
    else:
        raise ValueError("PHYSICALDRIVE%s does not exist", disk_num)
    return size

def get_drive_size(disk_num):
    """Get Windows Drive size.

    Args:
        disk_num(int): The Physical Drive Number
            e.g. for PHYSICALDRIVE0 put 0
    Returns:
        Human readable string of the drive size
    """
    output = query_diskpart("list disk\n")
    drive_size = match_drive_size(output, disk_num)
    return drive_size

if __name__ == "__main__":
    print(get_drive_size(0))