summaryrefslogtreecommitdiffstats
path: root/raid.py
blob: aa65a84d4cf1790b352890f4c2fd30875fd2e6ed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
#!/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."""

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

# XXX define availraidlevels and defaultmntpts as arch characteristics
availRaidLevels = getRaidLevels()

import parted
import isys
import os
import partitioning
import partedUtils

import logging
log = logging.getLogger("anaconda")

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

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.error("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.error("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.error("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.warning("missing components of raid device md%d.  The "
                        "raid device needs %d drive(s) and only %d (was/were) "
                        "found. This raid device will not be started.", mdMinor,
                        totalDisks, len(devices))
	    continue
	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 in ("RAID6", "6", 6):
        return True
    return False

def isRaid5(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID5."""
    if raidlevel in ("RAID5", "5", 5):
        return True
    return False

def isRaid1(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID1."""
    if raidlevel in ("mirror", "RAID1", "1", 1):
        return True
    return False

def isRaid0(raidlevel):
    """Return whether raidlevel is a valid descriptor of RAID0."""
    if raidlevel in ("stripe", "RAID0", "0", 0):
        return True
    return False

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 2
    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"