查找包含给定文件的文件系统的大小和可用空间

Question

我在Linux上使用Python 2.6.最快的方法是什么:

• 确定哪个分区包含给定目录或文件？

  例如,假设它/dev/sda2已安装在/home,并/dev/mapper/foo已安装/home/foo.从字符串"/home/foo/bar/baz"我想恢复这对("/dev/mapper/foo", "home/foo").

• 然后,获取给定分区的使用情况统计信息？例如,给定/dev/mapper/foo我想获得分区的大小和可用的可用空间(以字节或大约以兆字节为单位).

Answer 1

这不会给出分区的名称,但您可以使用statvfsUnix系统调用直接获取文件系统统计信息.要从Python调用它,请使用os.statvfs('/home/foo/bar/baz').

根据POSIX,结果中的相关字段:

unsigned long f_frsize   Fundamental file system block size. 
fsblkcnt_t    f_blocks   Total number of blocks on file system in units of f_frsize. 
fsblkcnt_t    f_bfree    Total number of free blocks. 
fsblkcnt_t    f_bavail   Number of free blocks available to 
                         non-privileged process.

因此,要理解价值观,请乘以f_frsize:

import os
statvfs = os.statvfs('/home/foo/bar/baz')

statvfs.f_frsize * statvfs.f_blocks     # Size of filesystem in bytes
statvfs.f_frsize * statvfs.f_bfree      # Actual number of free bytes
statvfs.f_frsize * statvfs.f_bavail     # Number of free bytes that ordinary users
                                        # are allowed to use (excl. reserved space)

Answer 2

如果您只需要设备上的可用空间,请参阅os.statvfs()下面的答案.

如果还需要与文件关联的设备名称和挂载点,则应调用外部程序以获取此信息.df将提供您需要的所有信息 - 在调用df filename时打印关于包含该文件的分区的行.

举个例子:

import subprocess
df = subprocess.Popen(["df", "filename"], stdout=subprocess.PIPE)
output = df.communicate()[0]
device, size, used, available, percent, mountpoint = \
    output.split("\n")[1].split()

请注意,这是相当脆弱的,因为它取决于df输出的确切格式,但我不知道更强大的解决方案.(有一些解决方案依赖于/proc下面的文件系统,它们比这个更不便携.)

Answer 3

import os

def get_mount_point(pathname):
    "Get the mount point of the filesystem containing pathname"
    pathname= os.path.normcase(os.path.realpath(pathname))
    parent_device= path_device= os.stat(pathname).st_dev
    while parent_device == path_device:
        mount_point= pathname
        pathname= os.path.dirname(pathname)
        if pathname == mount_point: break
        parent_device= os.stat(pathname).st_dev
    return mount_point

def get_mounted_device(pathname):
    "Get the device mounted at pathname"
    # uses "/proc/mounts"
    pathname= os.path.normcase(pathname) # might be unnecessary here
    try:
        with open("/proc/mounts", "r") as ifp:
            for line in ifp:
                fields= line.rstrip('\n').split()
                # note that line above assumes that
                # no mount points contain whitespace
                if fields[1] == pathname:
                    return fields[0]
    except EnvironmentError:
        pass
    return None # explicit

def get_fs_freespace(pathname):
    "Get the free space of the filesystem containing pathname"
    stat= os.statvfs(pathname)
    # use f_bfree for superuser, or f_bavail if filesystem
    # has reserved space for superuser
    return stat.f_bfree*stat.f_bsize

我的计算机上的一些示例路径名:

path 'trash':
  mp /home /dev/sda4
  free 6413754368
path 'smov':
  mp /mnt/S /dev/sde
  free 86761562112
path '/usr/local/lib':
  mp / rootfs
  free 2184364032
path '/proc/self/cmdline':
  mp /proc proc
  free 0

PS

如果在Python≥3.3上shutil.disk_usage(path),则会返回以(total, used, free)字节表示的命名元组.

Answer 4

从Python 3.3开始,使用标准库可以轻松直接地执行此操作:

$ cat free_space.py 
#!/usr/bin/env python3

import shutil

total, used, free = shutil.disk_usage(__file__)
print(total, used, free)

$ ./free_space.py 
1007870246912 460794834944 495854989312

这些数字以字节为单位.有关详细信息,请参阅文档.

Answer 5

这应该让你问的一切:

import os
from collections import namedtuple

disk_ntuple = namedtuple('partition',  'device mountpoint fstype')
usage_ntuple = namedtuple('usage',  'total used free percent')

def disk_partitions(all=False):
    """Return all mountd partitions as a nameduple.
    If all == False return phyisical partitions only.
    """
    phydevs = []
    f = open("/proc/filesystems", "r")
    for line in f:
        if not line.startswith("nodev"):
            phydevs.append(line.strip())

    retlist = []
    f = open('/etc/mtab', "r")
    for line in f:
        if not all and line.startswith('none'):
            continue
        fields = line.split()
        device = fields[0]
        mountpoint = fields[1]
        fstype = fields[2]
        if not all and fstype not in phydevs:
            continue
        if device == 'none':
            device = ''
        ntuple = disk_ntuple(device, mountpoint, fstype)
        retlist.append(ntuple)
    return retlist

def disk_usage(path):
    """Return disk usage associated with path."""
    st = os.statvfs(path)
    free = (st.f_bavail * st.f_frsize)
    total = (st.f_blocks * st.f_frsize)
    used = (st.f_blocks - st.f_bfree) * st.f_frsize
    try:
        percent = ret = (float(used) / total) * 100
    except ZeroDivisionError:
        percent = 0
    # NB: the percentage is -5% than what shown by df due to
    # reserved blocks that we are currently not considering:
    # http://goo.gl/sWGbH
    return usage_ntuple(total, used, free, round(percent, 1))


if __name__ == '__main__':
    for part in disk_partitions():
        print part
        print "    %s\n" % str(disk_usage(part.mountpoint))

在我的盒子上面打印代码:

giampaolo@ubuntu:~/dev$ python foo.py 
partition(device='/dev/sda3', mountpoint='/', fstype='ext4')
    usage(total=21378641920, used=4886749184, free=15405903872, percent=22.9)

partition(device='/dev/sda7', mountpoint='/home', fstype='ext4')
    usage(total=30227386368, used=12137168896, free=16554737664, percent=40.2)

partition(device='/dev/sdb1', mountpoint='/media/1CA0-065B', fstype='vfat')
    usage(total=7952400384, used=32768, free=7952367616, percent=0.0)

partition(device='/dev/sr0', mountpoint='/media/WB2PFRE_IT', fstype='iso9660')
    usage(total=695730176, used=695730176, free=0, percent=100.0)

partition(device='/dev/sda6', mountpoint='/media/Dati', fstype='fuseblk')
    usage(total=914217758720, used=614345637888, free=299872120832, percent=67.2)

Answer 6

找出它的最简单方法.

import os
from collections import namedtuple

DiskUsage = namedtuple('DiskUsage', 'total used free')

def disk_usage(path):
    """Return disk usage statistics about the given path.

    Will return the namedtuple with attributes: 'total', 'used' and 'free',
    which are the amount of total, used and free space, in bytes.
    """
    st = os.statvfs(path)
    free = st.f_bavail * st.f_frsize
    total = st.f_blocks * st.f_frsize
    used = (st.f_blocks - st.f_bfree) * st.f_frsize
    return DiskUsage(total, used, free)

Answer 7

对于问题的第二部分，“获取给定分区的使用统计信息”，psutil使用disk_usage(path)函数使这变得容易。给定一个路径，disk_usage()返回一个命名元组，包括以字节表示的总空间、已用空间和可用空间，以及使用百分比。

文档中的简单示例：

>>> import psutil
>>> psutil.disk_usage('/')
sdiskusage(total=21378641920, used=4809781248, free=15482871808, percent=22.5)

Psutil 适用于从 2.6 到 3.6 的 Python 版本以及 Linux、Windows 和 OSX 等平台。

Answer 8

对于第一点,您可以尝试使用os.path.realpath获取规范路径,检查它/etc/mtab(我实际建议调用getmntent,但我找不到正常的访问方式)来找到最长匹配.(当然,您可能应该stat同时使用文件和假定的挂载点来验证它们实际上是在同一设备上)

对于第二点,用于os.statvfs获取块大小和使用信息.

(免责声明:我没有测试过这一点,我知道的大部分来自coreutils来源)

Answer 9

import os

def disk_stat(path):
    disk = os.statvfs(path)
    percent = (disk.f_blocks - disk.f_bfree) * 100 / (disk.f_blocks -disk.f_bfree + disk.f_bavail) + 1
    return percent


print disk_stat('/')
print disk_stat('/data')