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	#!/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