1LVREDUCE(8) System Manager's Manual LVREDUCE(8)
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6 lvreduce - Reduce the size of a logical volume
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9 lvreduce option_args position_args
10 [ option_args ]
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13 lvreduce reduces the size of an LV. The freed logical extents are
14 returned to the VG to be used by other LVs. A copy-on-write snapshot LV
15 can also be reduced if less space is needed to hold COW blocks. Use
16 lvconvert(8) to change the number of data images in a RAID or mirrored
17 LV.
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19 Be careful when reducing an LV's size, because data in the reduced area
20 is lost. Ensure that any file system on the LV is resized before run‐
21 ning lvreduce so that the removed extents are not in use by the file
22 system.
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24 Sizes will be rounded if necessary. For example, the LV size must be an
25 exact number of extents, and the size of a striped segment must be a
26 multiple of the number of stripes.
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28 In the usage section below, --size Size can be replaced with --extents
29 Number. See both descriptions the options section.
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32 lvreduce -L|--size [-]Size[m|UNIT] LV
33 [ -l|--extents [-]Number[PERCENT] ]
34 [ -A|--autobackup y|n ]
35 [ -f|--force ]
36 [ -n|--nofsck ]
37 [ -r|--resizefs ]
38 [ --noudevsync ]
39 [ --reportformat basic|json ]
40 [ COMMON_OPTIONS ]
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42 Common options for lvm:
43 [ -d|--debug ]
44 [ -h|--help ]
45 [ -q|--quiet ]
46 [ -t|--test ]
47 [ -v|--verbose ]
48 [ -y|--yes ]
49 [ --commandprofile String ]
50 [ --config String ]
51 [ --driverloaded y|n ]
52 [ --lockopt String ]
53 [ --longhelp ]
54 [ --profile String ]
55 [ --version ]
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58 -A|--autobackup y|n
59 Specifies if metadata should be backed up automatically after a
60 change. Enabling this is strongly advised! See vgcfgbackup(8)
61 for more information.
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63 --commandprofile String
64 The command profile to use for command configuration. See
65 lvm.conf(5) for more information about profiles.
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67 --config String
68 Config settings for the command. These override lvm.conf set‐
69 tings. The String arg uses the same format as lvm.conf, or may
70 use section/field syntax. See lvm.conf(5) for more information
71 about config.
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73 -d|--debug ...
74 Set debug level. Repeat from 1 to 6 times to increase the detail
75 of messages sent to the log file and/or syslog (if configured).
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77 --driverloaded y|n
78 If set to no, the command will not attempt to use device-mapper.
79 For testing and debugging.
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81 -l|--extents [-]Number[PERCENT]
82 Specifies the new size of the LV in logical extents. The --size
83 and --extents options are alternate methods of specifying size.
84 The total number of physical extents used will be greater when
85 redundant data is needed for RAID levels. An alternate syntax
86 allows the size to be determined indirectly as a percentage of
87 the size of a related VG, LV, or set of PVs. The suffix %VG
88 denotes the total size of the VG, the suffix %FREE the remaining
89 free space in the VG, and the suffix %PVS the free space in the
90 specified PVs. For a snapshot, the size can be expressed as a
91 percentage of the total size of the origin LV with the suffix
92 %ORIGIN (100%ORIGIN provides space for the whole origin). When
93 expressed as a percentage, the size defines an upper limit for
94 the number of logical extents in the new LV. The precise number
95 of logical extents in the new LV is not determined until the
96 command has completed. When the plus + or minus - prefix is
97 used, the value is not an absolute size, but is relative and
98 added or subtracted from the current size.
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100 -f|--force ...
101 Override various checks, confirmations and protections. Use
102 with extreme caution.
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104 -h|--help
105 Display help text.
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107 --lockopt String
108 Used to pass options for special cases to lvmlockd. See lvm‐
109 lockd(8) for more information.
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111 --longhelp
112 Display long help text.
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114 -n|--nofsck
115 Do not perform fsck before resizing filesystem when filesystem
116 requires it. You may need to use --force to proceed with this
117 option.
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119 --noudevsync
120 Disables udev synchronisation. The process will not wait for
121 notification from udev. It will continue irrespective of any
122 possible udev processing in the background. Only use this if
123 udev is not running or has rules that ignore the devices LVM
124 creates.
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126 --profile String
127 An alias for --commandprofile or --metadataprofile, depending on
128 the command.
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130 -q|--quiet ...
131 Suppress output and log messages. Overrides --debug and --ver‐
132 bose. Repeat once to also suppress any prompts with answer
133 'no'.
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135 --reportformat basic|json
136 Overrides current output format for reports which is defined
137 globally by the report/output_format setting in lvm.conf. basic
138 is the original format with columns and rows. If there is more
139 than one report per command, each report is prefixed with the
140 report name for identification. json produces report output in
141 JSON format. See lvmreport(7) for more information.
142
143 -r|--resizefs
144 Resize underlying filesystem together with the LV using
145 fsadm(8).
146
147 -L|--size [-]Size[m|UNIT]
148 Specifies the new size of the LV. The --size and --extents
149 options are alternate methods of specifying size. The total
150 number of physical extents used will be greater when redundant
151 data is needed for RAID levels. When the plus + or minus - pre‐
152 fix is used, the value is not an absolute size, but is relative
153 and added or subtracted from the current size.
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155 -t|--test
156 Run in test mode. Commands will not update metadata. This is
157 implemented by disabling all metadata writing but nevertheless
158 returning success to the calling function. This may lead to
159 unusual error messages in multi-stage operations if a tool
160 relies on reading back metadata it believes has changed but
161 hasn't.
162
163 -v|--verbose ...
164 Set verbose level. Repeat from 1 to 4 times to increase the
165 detail of messages sent to stdout and stderr.
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167 --version
168 Display version information.
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170 -y|--yes
171 Do not prompt for confirmation interactively but always assume
172 the answer yes. Use with extreme caution. (For automatic no,
173 see -qq.)
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176 LV
177 Logical Volume name. See lvm(8) for valid names. An LV posi‐
178 tional arg generally includes the VG name and LV name, e.g.
179 VG/LV.
180
181 String
182 See the option description for information about the string con‐
183 tent.
184
185 Size[UNIT]
186 Size is an input number that accepts an optional unit. Input
187 units are always treated as base two values, regardless of capi‐
188 talization, e.g. 'k' and 'K' both refer to 1024. The default
189 input unit is specified by letter, followed by |UNIT. UNIT rep‐
190 resents other possible input units: bBsSkKmMgGtTpPeE. b|B is
191 bytes, s|S is sectors of 512 bytes, k|K is kilobytes, m|M is
192 megabytes, g|G is gigabytes, t|T is terabytes, p|P is petabytes,
193 e|E is exabytes. (This should not be confused with the output
194 control --units, where capital letters mean multiple of 1000.)
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197 See lvm(8) for information about environment variables used by lvm.
198 For example, LVM_VG_NAME can generally be substituted for a required VG
199 parameter.
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202 Reduce the size of an LV by 3 logical extents:
203 lvreduce -l -3 vg00/lvol1
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206 lvm(8) lvm.conf(5) lvmconfig(8)
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208 pvchange(8) pvck(8) pvcreate(8) pvdisplay(8) pvmove(8) pvremove(8)
209 pvresize(8) pvs(8) pvscan(8)
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211 vgcfgbackup(8) vgcfgrestore(8) vgchange(8) vgck(8) vgcreate(8) vgcon‐
212 vert(8) vgdisplay(8) vgexport(8) vgextend(8) vgimport(8) vgimport‐
213 clone(8) vgmerge(8) vgmknodes(8) vgreduce(8) vgremove(8) vgrename(8)
214 vgs(8) vgscan(8) vgsplit(8)
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216 lvcreate(8) lvchange(8) lvconvert(8) lvdisplay(8) lvextend(8) lvre‐
217 duce(8) lvremove(8) lvrename(8) lvresize(8) lvs(8) lvscan(8)
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219 lvm-fullreport(8) lvm-lvpoll(8) lvm2-activation-generator(8) blkdeacti‐
220 vate(8) lvmdump(8)
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222 dmeventd(8) lvmetad(8) lvmpolld(8) lvmlockd(8) lvmlockctl(8) clvmd(8)
223 cmirrord(8) lvmdbusd(8)
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225 lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)
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229Red Hat, Inc. LVM TOOLS 2.02.183(2) (2018-12-07) LVREDUCE(8)