"""
Mdstat - file ``/proc/mdstat``
==============================
Represents the information in the ``/proc/mdstat`` file. Several
examples of possible data containe in the file can be found on the
`MDstat kernel.org wiki page <https://raid.wiki.kernel.org/index.php/Mdstat>`_.
In particular, the discussion here will focus on initial extraction of information
form lines such as::
Personalities : [raid1] [raid6] [raid5] [raid4]
md1 : active raid1 sdb2[1] sda2[0]
136448 blocks [2/2] [UU]
md2 : active raid1 sdb3[1] sda3[0]
129596288 blocks [2/2] [UU]
md3 : active raid5 sdl1[9] sdk1[8] sdj1[7] sdi1[6] sdh1[5] sdg1[4] sdf1[3] sde1[2] sdd1[1] sdc1[0]
1318680576 blocks level 5, 1024k chunk, algorithm 2 [10/10] [UUUUUUUUUU]
The data contained in ``mdstat`` is represented with three top level members -
``personalities``, ``components`` and ``mds``.
Examples:
>>> mdstat = shared[Mdstat]
>>> mdstat.personalities
['raid1', 'raid6', 'raid5', 'raid4']
>>> len(mdstat.components) # The individual component devices
14
>>> mdstat.components[0]['device_name']
'md1'
>>> sdb2 = mdstat.components[0]
>>> sdb2['component_name']
'sdb2'
>>> sdb2['active']
True
>>> sdb2['raid']
'raid1'
>>> sdb2['role']
1
>>> sdb2['up']
True
>>> sorted(mdstat.mds.keys()) # dictionary of MD devices by device name
['md1', 'md2', 'md3']
>>> mdstat.mds['md1']['active']
True
>>> len(mdstat.mds['md1']['devices']) # list of devices in this MD
2
>>> mdstat.mds['md1']['devices'][0]['component_name'] # device information
'sdb2'
"""
import re
from .. import parser, CommandParser
from insights.specs import Specs
[docs]@parser(Specs.mdstat)
class Mdstat(CommandParser):
"""
Represents the information in the ``/proc/mdstat`` file.
Attributes
----------
personalities : list
A list of RAID levels the kernel currently supports
components : list of dicts
A list containing a dict of md component device information
Each of these dicts contains the following keys
- ``device_name`` : string - name of the array device
- ``active`` : boolean - ``True`` if the array is active, ``False``
if it is inactive.
- ``component_name`` : string - name of the component device
- ``raid`` : string - with the raid level, e.g., "raid1" for "md1"
- ``role`` : int - raid role number
- ``device_flag`` : str - device component status flag. Known values
include 'F' (failed device), 'S', and 'W'
- ``up`` : boolean - ``True`` if the component device is up
- ``auto_read_only`` : boolean - ``True`` if the array device is
"auto-read-only"
- ``blocks`` : the number of blocks in the device
- ``level`` : the current RAID level, if found in the status line
- ``chunk`` : the device chunk size, if found in the status line
- ``algorithm`` : the current conflict resolution algorithm, if found
in the status line
mds : dict of dicts
A dictionary keyed on the MD device name, with the following keys
- ``name``: Name of the MD device
- ``active``: Whether the MD device is active
- ``raid``: The RAID type string
- ``devices``: a list of the devices in this
- ``blocks``, ``level``, ``chunk`` and ``algorithm`` - the same
information given above per component device (if found)
"""
[docs] def parse_content(self, content):
self.mds = {}
self.components = []
self.personalities = []
current_components = None
in_component = False
for line in content:
line = line.strip()
if line.startswith('Personalities'):
in_component = False
self.personalities = parse_personalities(line)
elif line.startswith("md"): # Starting a component array stanza
in_component = True
current_components = parse_array_start(line)
elif not line: # blank line, ending a component array stanza
if in_component:
self.components.extend(current_components)
current_components = None
in_component = False
else:
if in_component:
parse_array_status(line, current_components)
upstring = parse_upstring(line)
if upstring:
apply_upstring(upstring, current_components)
# Map component devices into MDs dictionary by device name
for comp in self.components:
devname = comp['device_name']
if devname not in self.mds:
# md2 : active raid1 sdb3[1] sda3[0]
# 129596288 blocks [2/2] [UU]
self.mds[devname] = {
'name': devname, 'active': comp['active'],
'raid': comp['raid'], 'blocks': comp['blocks'],
'devices': []
}
for opt in ['level', 'chunk', 'algorithm']:
if opt in comp:
self.mds[devname][opt] = comp[opt]
self.mds[devname]['devices'].append(dict(
(k, comp[k]) for k in comp if k in ['component_name', 'role', 'up']
))
# Keep self.data just for backwards compat
self.data = {
'personalities': self.personalities,
'components': self.components
}
[docs]def parse_personalities(personalities_line):
"""Parse the "personalities" line of ``/proc/mdstat``.
Lines are expected to be like:
Personalities : [linear] [raid0] [raid1] [raid5] [raid4] [raid6]
If they do not have this format, an error will be raised since it
would be considered an unexpected parsing error.
Parameters
----------
personalities_line : str
A single "Personalities" line from an ``/proc/mdstat`` files.
Returns
-------
A list of raid "personalities" listed on the line.
"""
tokens = personalities_line.split()
assert tokens.pop(0) == "Personalities"
assert tokens.pop(0) == ":"
personalities = []
for token in tokens:
assert token.startswith('[') and token.endswith(']')
personalities.append(token.strip('[]'))
return personalities
[docs]def parse_array_start(md_line):
"""Parse the initial line of a device array stanza in
``/proc/mdstat``.
Lines are expected to be like:
md2 : active raid1 sdb3[1] sda3[0]
If they do not have this format, an error will be raised since it
would be considered an unexpected parsing error.
Parameters
----------
md_line : str
A single line from the start of a device array stanza from a
``/proc/mdstat`` file.
Returns
-------
A list of dictionaries, one dictionrary for each component
device making up the array.
"""
components = []
tokens = md_line.split()
device_name = tokens.pop(0)
assert device_name.startswith("md")
assert tokens.pop(0) == ":"
active_string = tokens.pop(0)
active = False
if active_string == "active":
active = True
else:
assert active_string == "inactive"
raid_read_only_token = tokens.pop(0)
auto_read_only = False
raid = None
if raid_read_only_token == "(auto-read-only)":
auto_read_only = True
raid = tokens.pop(0)
elif active:
raid = raid_read_only_token
else: # Inactive devices don't list the raid type
raid = None
tokens.insert(0, raid_read_only_token)
for token in tokens:
subtokens = re.split(r"\[|]", token)
assert len(subtokens) > 1
comp_name = subtokens[0]
assert comp_name
role = int(subtokens[1])
device_flag = None
if len(subtokens) > 2:
device_flag = subtokens[2]
if device_flag:
device_flag = device_flag.strip('()')
component_row = {"device_name": device_name,
"raid": raid,
"active": active,
"auto_read_only": auto_read_only,
"component_name": comp_name,
"role": role,
"device_flag": device_flag}
components.append(component_row)
return components
[docs]def parse_array_status(line, components):
"""
Parse the array status line, e.g.::
1318680576 blocks level 5, 1024k chunk, algorithm 2 [10/10] [UUUUUUUUUU]
This retrieves the following pieces of information:
* ``blocks`` - (int) number of blocks in the whole MD device (always present)
* ``level`` - (int) if found, the present RAID level
* ``chunksize`` - (str) if found, the size of the data chunk in kilobytes
* ``algorithm`` - (int) if found, the current algorithm in use.
Because of the way data is stored per-component and not per-array, this
then puts the above keys into each of the component dictionaries in the
list we've been given.
Sample data::
1250241792 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/5] [UUUUUU]
1465151808 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
136448 blocks [2/2] [UU]
6306 blocks super external:imsm<Paste>
"""
status_line_re = r'(?P<blocks>\d+) blocks' + \
r'(?: super (?P<super>\S+))?' + \
r'(?: level (?P<level>\d+),)?' + \
r'(?: (?P<chunk>\d+k) chunk,)?' + \
r'(?: algorithm (?P<algorithm>\d+))?'
# Since we're only called once per line, unless there's a good way to
# cache this regular expression in compiled form we're going to have to
# compile it each time.
status_line_rex = re.compile(status_line_re)
match = status_line_rex.search(line)
if match:
attributes = {'blocks': int(match.group('blocks'))}
if match.group('level'):
attributes['level'] = int(match.group('level'))
if match.group('chunk'):
attributes['chunk'] = match.group('chunk')
if match.group('algorithm'):
attributes['algorithm'] = int(match.group('algorithm'))
for comp in components:
comp.update(attributes)
[docs]def parse_upstring(line):
"""
Parse the subsequent lines of a device array stanza in ``/proc/mdstat``
for the "up" indictor string.
Lines are expected to be like:
129596288 blocks [2/2] [UU]
or
1318680576 blocks level 5, 1024k chunk, algorithm 2 [10/10] [UUU_UUUUUU]
In particular, this method searchs for the string like ``[UU]`` which
indicates whether component devices or up, ``U`` or down, ``_``.
Parameters
----------
line : str
A single line from a device array stanza.
Returns
-------
The string containing a series of ``U`` and ``\_`` characters if
found in the string, and ``None`` if the uptime string is not found.
"""
UP_STRING_REGEX = r"\[(U|_)+]"
match = re.search(UP_STRING_REGEX, line)
if match:
return match.group().strip('[]')
else:
return None
[docs]def apply_upstring(upstring, component_list):
"""Update the dictionaries resulting from ``parse_array_start`` with
the "up" key based on the upstring returned from ``parse_upstring``.
The function assumes that the upstring and component_list parameters
passed in are from the same device array stanza of a
``/proc/mdstat`` file.
The function modifies component_list in place, adding or updating
the value of the "up" key to True if there is a corresponding ``U``
in the upstring string, or to False if there is a corresponding
``_``.
If there the number of rows in component_list does not match the
number of characters in upstring, an ``AssertionError`` is raised.
Parameters
----------
upstring : str
String sequence of ``U``s and ``_``s as determined by the
``parse_upstring`` method
component_list : list
List of dictionaries output from the ``parse_array_start`` method.
"""
assert len(upstring) == len(component_list)
def add_up_key(comp_dict, up_indicator):
assert up_indicator == 'U' or up_indicator == "_"
comp_dict['up'] = up_indicator == 'U'
for comp_dict, up_indicator in zip(component_list, upstring):
add_up_key(comp_dict, up_indicator)