IOError：设备上没有剩余空间 - 哪个设备？

我正在将一个小文件 (8.5 Mb) 上传到 Flask 测试服务器。

文件上传完成后，服务器报告：

    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/wtforms/form.py", 
        line 212, in __call__
    return type.__call__(cls, *args, **kwargs)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/flask_wtf/form.py", line 49, in __init__
        formdata = request.form
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/local.py", 
        line 338, in __getattr__
    return getattr(self._get_current_object(), name)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/utils.py", 
         line 71, in __get__
    value = self.func(obj)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/wrappers.py", 
         line 484, in form
    self._load_form_data()
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/flask/wrappers.py", 
        line 165, in _load_form_data
    RequestBase._load_form_data(self)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/wrappers.py", 
        line 356, in _load_form_data
    mimetype, content_length, options)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py", 
        line 193, in parse
    content_length, options)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py",
        line 99, in wrapper
    return f(self, stream, *args, **kwargs)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py",
        line 210, in _parse_multipart
    form, files = parser.parse(stream, boundary, content_length)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py", 
        line 520, in parse
    return self.cls(form), self.cls(files)
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/datastructures.py", 
        line 373, in __init__
    for key, value in mapping or ():
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py", 
        line 518, in <genexpr>
    form = (p[1] for p in formstream if p[0] == 'form')
    File "/home/ubuntu/.virtualenvs/eco_app/lib/python2.7/site-packages/werkzeug/formparser.py", 
        line 494, in parse_parts
        _write(ell)
IOError: [Errno 28] No space left on device

现在，服务器有足够的可用空间 - 超过 3Gb。

我看过Werkzeug github 存储库 https://github.com/mitsuhiko/werkzeug/blob/master/werkzeug/formparser.py尝试找到 Werkzeug 尝试写入的位置，但无法追踪到它。

我也检查过临时文件.gettempdir() http://flask.pocoo.org/docs/0.10/patterns/fileuploads/它提供 /var/tmp 作为临时文件目录，但该文件夹实际上是空的，所以我认为这不是造成问题的位置。

如何找到没有空间的设备？

@Tom Hunt 的评论是正确的。

这个 unix SE 答案解释了发生了什么 https://unix.stackexchange.com/questions/60731/overflow-tmp-mounted-when-there-is-free-space-on.

为了防止磁盘空间不足，如果根分区磁盘空间不足，某些守护程序会自动使用 ram 磁盘“隐藏”当前 /tmp/ 目录。遗憾的是，一旦有足够的磁盘空间再次空闲，该过程就不会自动恢复。

我卸载了 /tmp 目录并遵循 Nitesh 的建议：

sudo umount /tmp
sudo echo 'MINTMPKB=0' > sudo /etc/default/mountoverflowtmp

现在上传工作正常。