cdrom.image/updates/raid.py

#!/usr/bin/python
#
# raid.py - raid probing control
#
# Erik Troan <ewt@redhat.com>
#
# Copyright 1999-2002 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# library public license.
#
# You should have received a copy of the GNU Library Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
"""Raid probing control."""

import parted
import isys
import os
import partitioning
import partedUtils

from rhpl.log import log

# these arches can have their /boot on RAID and not have their
# boot loader blow up
raidBootArches = [ "i386", "x86_64" ]

def scanForRaid(drives):
    """Scans for raid devices on drives.

    drives is a list of device names.
    Returns a list of (mdMinor, devices, level, totalDisks) tuples.
    """
    
    raidSets = {}
    raidDevices = {}

    for d in drives:
        parts = []
        isys.makeDevInode(d, "/tmp/" + d)
        try:
            dev = parted.PedDevice.get("/tmp/" + d)
            disk = parted.PedDisk.new(dev)

            raidParts = partedUtils.get_raid_partitions(disk)
            for part in raidParts:
                parts.append(partedUtils.get_partition_name(part))
        except:
            pass

        os.remove("/tmp/" + d)
        for dev in parts:
            try:
                (major, minor, raidSet, level, nrDisks, totalDisks, mdMinor) =\
                        isys.raidsb(dev)
            except ValueError:
                # bad magic, this can't be part of our raid set
                log("reading raid sb failed for %s",dev)
                continue

            if raidSets.has_key(raidSet):
                (knownLevel, knownDisks, knownMinor, knownDevices) = \
                        raidSets[raidSet]
                if knownLevel != level or knownDisks != totalDisks or \
                   knownMinor != mdMinor:
                    # Raise hell
                    log("raid set inconsistency for md%d: "
                        "all drives in this raid set do not "
                        "agree on raid parameters.  Skipping raid device",
                        mdMinor)
                    continue
                knownDevices.append(dev)
                raidSets[raidSet] = (knownLevel, knownDisks, knownMinor,
                                     knownDevices)
            else:
                raidSets[raidSet] = (level, totalDisks, mdMinor, [dev,])

            if raidDevices.has_key(mdMinor):
                if (raidDevices[mdMinor] != raidSet):
                    log("raid set inconsistency for md%d: "
                        "found members of multiple raid sets "
                        "that claim to be md%d.  Using only the first "
                        "array found.", mdMinor, mdMinor)
                    continue
            else:
                raidDevices[mdMinor] = raidSet

    raidList = []
    for key in raidSets.keys():
        (level, totalDisks, mdMinor, devices) = raidSets[key]
        if len(devices) < totalDisks:
            log("missing components of raid device md%d.  The "
                "raid device needs %d drive(s) and only %d (was/were) found. "
                "This raid device will be started in degraded mode.", mdMinor,
                totalDisks, len(devices))
        raidList.append((mdMinor, devices, level, totalDisks))

    return raidList
                
def startAllRaid(driveList):
    """Do a raid start on raid devices and return a list like scanForRaid."""
    rc = []
    mdList = scanForRaid(driveList)
    for mdDevice, deviceList, level, numActive in mdList:
        devName = "md%d" % (mdDevice,)
        isys.raidstart(devName, deviceList[0])
        rc.append((devName, deviceList, level, numActive))
    return rc

def stopAllRaid(mdList):
    """Do a raid stop on each of the raid device tuples given."""
    for dev, devices, level, numActive in mdList:
        isys.raidstop(dev)

def isRaid6(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID6."""
    if raidlevel == "RAID6":
        return 1
    elif raidlevel == 6:
        return 1
    elif raidlevel == "6":
        return 1
    return 0

def isRaid5(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID5."""
    if raidlevel == "RAID5":
        return 1
    elif raidlevel == 5:
        return 1
    elif raidlevel == "5":
        return 1
    return 0

def isRaid1(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID1."""
    if raidlevel == "RAID1":
        return 1
    elif raidlevel == 1:
        return 1
    elif raidlevel == "1":
        return 1
    return 0

def isRaid0(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID0."""
    if raidlevel == "RAID0":
        return 1
    elif raidlevel == 0:
        return 1
    elif raidlevel == "0":
        return 1
    return 0

def get_raid_min_members(raidlevel):
    """Return the minimum number of raid members required for raid level"""
    if isRaid0(raidlevel):
        return 2
    elif isRaid1(raidlevel):
        return 1
    elif isRaid5(raidlevel):
        return 3
    elif isRaid6(raidlevel):
        return 4
    else:
        raise ValueError, "invalid raidlevel in get_raid_min_members"

def get_raid_max_spares(raidlevel, nummembers):
    """Return the maximum number of raid spares for raidlevel."""
    if isRaid0(raidlevel):
        return 0
    elif isRaid1(raidlevel) or isRaid5(raidlevel) or isRaid6(raidlevel):
        return max(0, nummembers - get_raid_min_members(raidlevel))
    else:
        raise ValueError, "invalid raidlevel in get_raid_max_spares"

def register_raid_device(mdname, newdevices, newlevel, newnumActive):
    """Register a new RAID device in the mdlist."""
    for dev, devices, level, numActive in partedUtils.DiskSet.mdList:
        if mdname == dev:
            if (devices != newdevices or level != newlevel or
                numActive != newnumActive):
                raise ValueError, "%s is already in the mdList!" % (mdname,)
            else:
                return
    partedUtils.DiskSet.mdList.append((mdname, newdevices[:], newlevel,
                                       newnumActive))

def lookup_raid_device(mdname):
    """Return the requested RAID device information."""
    for dev, devices, level, numActive in partedUtils.DiskSet.mdList:
        if mdname == dev:
            return (dev, devices, level, numActive)
    raise KeyError, "md device not found"

def getRaidLevels():
    avail = []
    try:
        f = open("/proc/mdstat", "r")
    except:
        pass
    else:
        for l in f.readlines():
            if not l.startswith("Personalities"):
                continue
            for tok in l.split():
                for lev in ("RAID0", "RAID1", "RAID5", "RAID6"):
                    if tok.upper().find(lev) != -1:
                        avail.append(lev)

        f.close()

    return avail


1	gordonr	1.1	#!/usr/bin/python
2			#
3			# raid.py - raid probing control
4			#
5			# Erik Troan <ewt@redhat.com>
6			#
7			# Copyright 1999-2002 Red Hat, Inc.
8			#
9			# This software may be freely redistributed under the terms of the GNU
10			# library public license.
11			#
12			# You should have received a copy of the GNU Library Public License
13			# along with this program; if not, write to the Free Software
14			# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
15			#
16			"""Raid probing control."""
17
18			import parted
19			import isys
20			import os
21			import partitioning
22			import partedUtils
23
24			from rhpl.log import log
25
26			# these arches can have their /boot on RAID and not have their
27			# boot loader blow up
28			raidBootArches = [ "i386", "x86_64" ]
29
30			def scanForRaid(drives):
31			"""Scans for raid devices on drives.
32
33			drives is a list of device names.
34			Returns a list of (mdMinor, devices, level, totalDisks) tuples.
35			"""
36
37			raidSets = {}
38			raidDevices = {}
39
40			for d in drives:
41			parts = []
42			isys.makeDevInode(d, "/tmp/" + d)
43			try:
44			dev = parted.PedDevice.get("/tmp/" + d)
45			disk = parted.PedDisk.new(dev)
46
47			raidParts = partedUtils.get_raid_partitions(disk)
48			for part in raidParts:
49			parts.append(partedUtils.get_partition_name(part))
50			except:
51			pass
52
53			os.remove("/tmp/" + d)
54			for dev in parts:
55			try:
56			(major, minor, raidSet, level, nrDisks, totalDisks, mdMinor) =\
57			isys.raidsb(dev)
58			except ValueError:
59			# bad magic, this can't be part of our raid set
60			log("reading raid sb failed for %s",dev)
61			continue
62
63			if raidSets.has_key(raidSet):
64			(knownLevel, knownDisks, knownMinor, knownDevices) = \
65			raidSets[raidSet]
66			if knownLevel != level or knownDisks != totalDisks or \
67			knownMinor != mdMinor:
68			# Raise hell
69			log("raid set inconsistency for md%d: "
70			"all drives in this raid set do not "
71			"agree on raid parameters. Skipping raid device",
72			mdMinor)
73			continue
74			knownDevices.append(dev)
75			raidSets[raidSet] = (knownLevel, knownDisks, knownMinor,
76			knownDevices)
77			else:
78			raidSets[raidSet] = (level, totalDisks, mdMinor, [dev,])
79
80			if raidDevices.has_key(mdMinor):
81			if (raidDevices[mdMinor] != raidSet):
82			log("raid set inconsistency for md%d: "
83			"found members of multiple raid sets "
84			"that claim to be md%d. Using only the first "
85			"array found.", mdMinor, mdMinor)
86			continue
87			else:
88			raidDevices[mdMinor] = raidSet
89
90			raidList = []
91			for key in raidSets.keys():
92			(level, totalDisks, mdMinor, devices) = raidSets[key]
93			if len(devices) < totalDisks:
94			log("missing components of raid device md%d. The "
95			"raid device needs %d drive(s) and only %d (was/were) found. "
96			"This raid device will be started in degraded mode.", mdMinor,
97			totalDisks, len(devices))
98			raidList.append((mdMinor, devices, level, totalDisks))
99
100			return raidList
101
102			def startAllRaid(driveList):
103			"""Do a raid start on raid devices and return a list like scanForRaid."""
104			rc = []
105			mdList = scanForRaid(driveList)
106			for mdDevice, deviceList, level, numActive in mdList:
107			devName = "md%d" % (mdDevice,)
108			isys.raidstart(devName, deviceList[0])
109			rc.append((devName, deviceList, level, numActive))
110			return rc
111
112			def stopAllRaid(mdList):
113			"""Do a raid stop on each of the raid device tuples given."""
114			for dev, devices, level, numActive in mdList:
115			isys.raidstop(dev)
116
117			def isRaid6(raidlevel):
118			"""Return whether raidlevel is a valid descriptor of RAID6."""
119			if raidlevel == "RAID6":
120			return 1
121			elif raidlevel == 6:
122			return 1
123			elif raidlevel == "6":
124			return 1
125			return 0
126
127			def isRaid5(raidlevel):
128			"""Return whether raidlevel is a valid descriptor of RAID5."""
129			if raidlevel == "RAID5":
130			return 1
131			elif raidlevel == 5:
132			return 1
133			elif raidlevel == "5":
134			return 1
135			return 0
136
137			def isRaid1(raidlevel):
138			"""Return whether raidlevel is a valid descriptor of RAID1."""
139			if raidlevel == "RAID1":
140			return 1
141			elif raidlevel == 1:
142			return 1
143			elif raidlevel == "1":
144			return 1
145			return 0
146
147			def isRaid0(raidlevel):
148			"""Return whether raidlevel is a valid descriptor of RAID0."""
149			if raidlevel == "RAID0":
150			return 1
151			elif raidlevel == 0:
152			return 1
153			elif raidlevel == "0":
154			return 1
155			return 0
156
157			def get_raid_min_members(raidlevel):
158			"""Return the minimum number of raid members required for raid level"""
159			if isRaid0(raidlevel):
160			return 2
161			elif isRaid1(raidlevel):
162			return 1
163			elif isRaid5(raidlevel):
164			return 3
165			elif isRaid6(raidlevel):
166			return 4
167			else:
168			raise ValueError, "invalid raidlevel in get_raid_min_members"
169
170			def get_raid_max_spares(raidlevel, nummembers):
171			"""Return the maximum number of raid spares for raidlevel."""
172			if isRaid0(raidlevel):
173			return 0
174			elif isRaid1(raidlevel) or isRaid5(raidlevel) or isRaid6(raidlevel):
175			return max(0, nummembers - get_raid_min_members(raidlevel))
176			else:
177			raise ValueError, "invalid raidlevel in get_raid_max_spares"
178
179			def register_raid_device(mdname, newdevices, newlevel, newnumActive):
180			"""Register a new RAID device in the mdlist."""
181			for dev, devices, level, numActive in partedUtils.DiskSet.mdList:
182			if mdname == dev:
183			if (devices != newdevices or level != newlevel or
184			numActive != newnumActive):
185			raise ValueError, "%s is already in the mdList!" % (mdname,)
186			else:
187			return
188			partedUtils.DiskSet.mdList.append((mdname, newdevices[:], newlevel,
189			newnumActive))
190
191			def lookup_raid_device(mdname):
192			"""Return the requested RAID device information."""
193			for dev, devices, level, numActive in partedUtils.DiskSet.mdList:
194			if mdname == dev:
195			return (dev, devices, level, numActive)
196			raise KeyError, "md device not found"
197
198			def getRaidLevels():
199			avail = []
200			try:
201			f = open("/proc/mdstat", "r")
202			except:
203			pass
204			else:
205			for l in f.readlines():
206			if not l.startswith("Personalities"):
207			continue
208			for tok in l.split():
209			for lev in ("RAID0", "RAID1", "RAID5", "RAID6"):
210			if tok.upper().find(lev) != -1:
211			avail.append(lev)
212
213			f.close()
214
215			return avail
216
217
218