1LVCONVERT(8) System Manager's Manual LVCONVERT(8)
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6 lvconvert - convert a logical volume from linear to mirror or snapshot
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9 lvconvert -m|--mirrors Mirrors [--mirrorlog {disk|core|mirrored}]
10 [--corelog] [-R|--regionsize MirrorLogRegionSize] [-A|--alloc Alloca‐
11 tionPolicy] [-b|--background] [-f|--force] [-i|--interval Seconds]
12 [-h|-?|--help] [--stripes Stripes [-I|--stripesize StripeSize]]
13 [--noudevsync] [-v|--verbose] [-y|--yes] [--version]
14 LogicalVolume[Path] [PhysicalVolume[Path][:PE[-PE]]...]
15 lvconvert --splitmirrors Images --name SplitLogicalVolumeName
17 MirrorLogicalVolume[Path] [SplittablePhysicalVolume[Path][:PE[-PE]]...]
18 lvconvert -s|--snapshot [-c|--chunksize ChunkSize] [-h|-?|--help]
20 [--noudevsync] [-v|--verbose] [-Z|--zero y|n] [--version]
21 OriginalLogicalVolume[Path] SnapshotLogicalVolume[Path]
22 lvconvert --merge [-b|--background] [-i|--interval Seconds]
24 [-h|-?|--help] [-v|--verbose] [--version] SnapshotLogicalVol‐
25 ume[Path]...
26 lvconvert --repair [-h|-?|--help] [-v|--verbose] [--version] Logi‐
28 calVolume[Path] [PhysicalVolume[Path]...]
29
31 lvconvert is used to change the segment type (i.e. linear, mirror, etc)
32 or characteristics of a logical volume. For example, it can add or
33 remove the redundant images of a logical volume, change the log type of
34 a mirror, or designate a logical volume as a snapshot repository.
35 If the conversion requires allocation of physical extents (for example,
36 when converting from linear to mirror) and you specify one or more
37 PhysicalVolumes (optionally with ranges of physical extents), alloca‐
38 tion of physical extents will be restricted to these physical extents.
39 If the conversion frees physical extents (for example, when converting
40 from a mirror to a linear, or reducing mirror legs) and you specify one
41 or more PhysicalVolumes, the freed extents come first from the speci‐
42 fied PhysicalVolumes.
43
45 See lvm for common options.
46 Exactly one of --splitmirrors, --mirrors, --repair, --snapshot or
47 --merge arguments is required.
48 -m, --mirrors Mirrors
50 Specifies the degree of the mirror you wish to create. For
51 example, "-m 1" would convert the original logical volume to a
52 mirror volume with 2-sides; that is, a linear volume plus one
53 copy.
54 --mirrorlog {disk|core|mirrored}
56 Specifies the type of log to use. The default is disk, which is
57 persistent and requires a small amount of storage space, usually
58 on a separate device from the data being mirrored. Core may be
59 useful for short-lived mirrors: It means the mirror is regener‐
60 ated by copying the data from the first device again every time
61 the device is activated - perhaps, for example, after every
62 reboot. Using "mirrored" will create a persistent log that is
63 itself mirrored.
64 --corelog
66 The optional argument "--corelog" is the same as specifying
67 "--mirrorlog core".
68 -R, --regionsize MirrorLogRegionSize
70 A mirror is divided into regions of this size (in MB), and the
71 mirror log uses this granularity to track which regions are in
72 sync.
73 -b, --background
75 Run the daemon in the background.
76 -i, --interval Seconds
78 Report progress as a percentage at regular intervals.
79 --noudevsync
81 Disable udev synchronisation. The process will not wait for
82 notification from udev. It will continue irrespective of any
83 possible udev processing in the background. You should only use
84 this if udev is not running or has rules that ignore the devices
85 LVM2 creates.
86 --splitmirrors Images
90 The number of redundant Images of a mirror to be split off and
91 used to form a new logical volume. A name must be supplied for
92 the newly-split-off logical volume using the --name argument.
93 -n Name
96 The name to apply to a logical volume which has been split off
97 from a mirror logical volume.
98 -s, --snapshot
102 Create a snapshot from existing logical volume using another
103 existing logical volume as its origin.
104 -c, --chunksize ChunkSize
106 Power of 2 chunk size for the snapshot logical volume between 4k
107 and 512k.
108 -Z, --zero y|n
110 Controls zeroing of the first KB of data in the snapshot. If
111 the volume is read-only the snapshot will not be zeroed.
112 --merge
114 Merges a snapshot into its origin volume. To check if your ker‐
115 nel supports this feature, look for 'snapshot-merge' in the out‐
116 put of 'dmsetup targets'. If both the origin and snapshot vol‐
117 ume are not open the merge will start immediately. Otherwise,
118 the merge will start the first time either the origin or snap‐
119 shot are activated and both are closed. Merging a snapshot into
120 an origin that cannot be closed, for example a root filesystem,
121 is deferred until the next time the origin volume is activated.
122 When merging starts, the resulting logical volume will have the
123 origin's name, minor number and UUID. While the merge is in
124 progress, reads or writes to the origin appear as they were
125 directed to the snapshot being merged. When the merge finishes,
126 the merged snapshot is removed. Multiple snapshots may be spec‐
127 ified on the commandline or a @tag may be used to specify multi‐
128 ple snapshots be merged to their respective origin.
129 --repair
133 Repair a mirror after suffering a disk failure. The mirror will
134 be brought back into a consistent state. By default, the origi‐
135 nal number of mirrors will be restored if possible. Specify -y
136 on the command line to skip the prompts. Use -f if you do not
137 want any replacement. Additionally, you may use --use-policies
138 to use the device replacement policy specified in lvm.conf, viz.
139 activation/mirror_log_fault_policy or activation/mir‐
140 ror_device_fault_policy.
141
143 "lvconvert -m1 vg00/lvol1"
144 converts the linear logical volume "vg00/lvol1" to a two-way mirror
145 logical volume.
146 "lvconvert --mirrorlog core vg00/lvol1"
148 converts a mirror with a disk log to a mirror with an in-memory log.
149 "lvconvert --mirrorlog disk vg00/lvol1"
151 converts a mirror with an in-memory log to a mirror with a disk log.
152 "lvconvert -m0 vg00/lvol1"
154 converts a mirror logical volume to a linear logical volume.
155 "lvconvert -s vg00/lvol1 vg00/lvol2"
157 converts logical volume "vg00/lvol2" to snapshot of original volume
158 "vg00/lvol1"
159 "lvconvert -m1 vg00/lvol1 /dev/sda:0-15 /dev/sdb:0-15"
161 converts linear logical volume "vg00/lvol1" to a two-way mirror, using
162 physical extents /dev/sda:0-15 and /dev/sdb:0-15 for allocation of new
163 extents.
164 "lvconvert -m0 vg00/lvmirror1 /dev/sda
166 converts mirror logical volume "vg00/lvmirror1" to linear, freeing
167 physical extents from /dev/sda.
168 "lvconvert --merge vg00/lvol1_snap"
170 merges "vg00/lvol1_snap" into its origin.
171 "lvconvert --merge @some_tag"
173 If vg00/lvol1, vg00/lvol2, and vg00/lvol3 are all tagged with
174 "some_tag" each snapshot logical volume will be merged serially, e.g.:
175 vg00/lvol1, then vg00/lvol2, then vg00/lvol3. If --background were
176 used it would start all snapshot logical volume merges in parallel.
177
180 lvm(8), vgcreate(8), lvremove(8), lvrename(8), lvextend(8), lvre‐
181 duce(8), lvdisplay(8), lvscan(8)
182Red Hat, Inc LVM TOOLS 2.02.84(2) (2011-02-09) LVCONVERT(8)