1LVCONVERT(8) System Manager's Manual LVCONVERT(8)
2
6 lvconvert - Change logical volume layout
7
9 lvconvert option_args position_args
10 [ option_args ]
11 [ position_args ]
12 --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit
14 -b|--background
15 -H|--cache
16 --cachedevice PV
17 --cachemetadataformat auto|1|2
18 --cachemode writethrough|writeback|passthrough
19 --cachepolicy String
20 --cachepool LV
21 --cachesettings String
22 --cachesize Size[m|UNIT]
23 --cachevol LV
24 -c|--chunksize Size[k|UNIT]
25 --commandprofile String
26 --compression y|n
27 --config String
28 -d|--debug
29 --deduplication y|n
30 --discards passdown|nopassdown|ignore
31 --driverloaded y|n
32 -f|--force
33 -h|--help
34 -i|--interval Number
35 --lockopt String
36 --longhelp
37 --merge
38 --mergemirrors
39 --mergesnapshot
40 --mergethin
41 --metadataprofile String
42 --mirrorlog core|disk
43 -m|--mirrors [+|-]Number
44 -n|--name String
45 --nolocking
46 --noudevsync
47 --originname LV
48 --poolmetadata LV
49 --poolmetadatasize Size[m|UNIT]
50 --poolmetadataspare y|n
51 --profile String
52 -q|--quiet
53 --raidintegrity y|n
54 --raidintegrityblocksize Number
55 --raidintegritymode String
56 -r|--readahead auto|none|Number
57 -R|--regionsize Size[m|UNIT]
58 --repair
59 --replace PV
60 -s|--snapshot
61 --splitcache
62 --splitmirrors Number
63 --splitsnapshot
64 --startpoll
65 --stripes Number
66 -I|--stripesize Size[k|UNIT]
67 --swapmetadata
68 -t|--test
69 -T|--thin
70 --thinpool LV
71 --trackchanges
72 --type linear|striped|snapshot|mir‐
73 ror|raid|thin|cache|vdo|thin-pool|cache-pool|vdo-pool
74 --uncache
75 --usepolicies
76 --vdopool LV
77 -v|--verbose
78 --version
79 -V|--virtualsize Size[m|UNIT]
80 -y|--yes
81 -Z|--zero y|n
82
84 lvconvert changes the LV type and includes utilities for LV data main‐
85 tenance. The LV type controls data layout and redundancy. The LV type
86 is also called the segment type or segtype.
87 To display the current LV type, run the command:
89 lvs -o name,segtype LV
91 In some cases, an LV is a single device mapper (dm) layer above physi‐
93 cal devices. In other cases, hidden LVs (dm devices) are layered
94 between the visible LV and physical devices. LVs in the middle layers
95 are called sub LVs. A command run on a visible LV sometimes operates
96 on a sub LV rather than the specified LV. In other cases, a sub LV
97 must be specified directly on the command line.
98 Sub LVs can be displayed with the command:
100 lvs -a
102 The linear type is equivalent to the striped type when one stripe
104 exists. In that case, the types can sometimes be used interchangably.
105 In most cases, the mirror type is deprecated and the raid1 type should
107 be used. They are both implementations of mirroring.
108 Striped raid types are raid0/raid0_meta, raid5 (an alias for raid5_ls),
110 raid6 (an alias for raid6_zr) and raid10 (an alias for raid10_near).
111 As opposed to mirroring, raid5 and raid6 stripe data and calculate par‐
113 ity blocks. The parity blocks can be used for data block recovery in
114 case devices fail. A maximum number of one device in a raid5 LV may
115 fail, and two in case of raid6. Striped raid types typically rotate the
116 parity and data blocks for performance reasons, thus avoiding con‐
117 tention on a single device. Specific arrangements of parity and data
118 blocks (layouts) can be used to optimize I/O performance, or to convert
119 between raid levels. See lvmraid(7) for more information.
120 Layouts of raid5 rotating parity blocks can be: left-asymmetric
122 (raid5_la), left-symmetric (raid5_ls with alias raid5), right-asymmet‐
123 ric (raid5_ra), right-symmetric (raid5_rs) and raid5_n, which doesn't
124 rotate parity blocks. Layouts of raid6 are: zero-restart (raid6_zr with
125 alias raid6), next-restart (raid6_nr), and next-continue (raid6_nc).
126 Layouts including _n allow for conversion between raid levels (raid5_n
128 to raid6 or raid5_n to striped/raid0/raid0_meta). Additionally, special
129 raid6 layouts for raid level conversions between raid5 and raid6 are:
130 raid6_ls_6, raid6_rs_6, raid6_la_6 and raid6_ra_6. Those correspond to
131 their raid5 counterparts (e.g. raid5_rs can be directly converted to
132 raid6_rs_6 and vice-versa).
133 raid10 (an alias for raid10_near) is currently limited to one data copy
135 and even number of sub LVs. This is a mirror group layout, thus a sin‐
136 gle sub LV may fail per mirror group without data loss.
137 Striped raid types support converting the layout, their stripesize and
139 their number of stripes.
140 The striped raid types combined with raid1 allow for conversion from
142 linear-> striped/raid0/raid0_meta and vice-versa by e.g. linear <->
143 raid1 <-> raid5_n (then adding stripes) <-> striped/raid0/raid0_meta.
144
146 Convert LV to linear.
147 lvconvert --type linear LV
149 [ COMMON_OPTIONS ]
150 [ PV ... ]
151 -
152 Convert LV to striped.
154 lvconvert --type striped LV
156 [ -I|--stripesize Size[k|UNIT] ]
157 [ -R|--regionsize Size[m|UNIT] ]
158 [ -i|--interval Number ]
159 [ --stripes Number ]
160 [ COMMON_OPTIONS ]
161 [ PV ... ]
162 -
163 Convert LV to type mirror (also see type raid1),
165 lvconvert --type mirror LV
167 [ -m|--mirrors [+|-]Number ]
168 [ -I|--stripesize Size[k|UNIT] ]
169 [ -R|--regionsize Size[m|UNIT] ]
170 [ -i|--interval Number ]
171 [ --stripes Number ]
172 [ --mirrorlog core|disk ]
173 [ COMMON_OPTIONS ]
174 [ PV ... ]
175 -
176 Convert LV to raid or change raid layout
178 (a specific raid level must be used, e.g. raid1).
179 lvconvert --type raid LV
181 [ -m|--mirrors [+|-]Number ]
182 [ -I|--stripesize Size[k|UNIT] ]
183 [ -R|--regionsize Size[m|UNIT] ]
184 [ -i|--interval Number ]
185 [ --stripes Number ]
186 [ COMMON_OPTIONS ]
187 [ PV ... ]
188 -
189 Convert LV to raid1 or mirror, or change number of mirror images.
191 lvconvert -m|--mirrors [+|-]Number LV
193 [ -R|--regionsize Size[m|UNIT] ]
194 [ -i|--interval Number ]
195 [ --mirrorlog core|disk ]
196 [ COMMON_OPTIONS ]
197 [ PV ... ]
198 -
199 Convert raid LV to change number of stripe images.
201 lvconvert --stripes Number LV_raid
203 [ -i|--interval Number ]
204 [ -R|--regionsize Size[m|UNIT] ]
205 [ -I|--stripesize Size[k|UNIT] ]
206 [ COMMON_OPTIONS ]
207 [ PV ... ]
208 -
209 Convert raid LV to change the stripe size.
211 lvconvert -I|--stripesize Size[k|UNIT] LV_raid
213 [ -i|--interval Number ]
214 [ -R|--regionsize Size[m|UNIT] ]
215 [ COMMON_OPTIONS ]
216 -
217 Split images from a raid1 or mirror LV and use them to create a new LV.
219 lvconvert --splitmirrors Number -n|--name LV_new LV_cache_mirror_raid1
221 [ COMMON_OPTIONS ]
222 [ PV ... ]
223 -
224 Split images from a raid1 LV and track changes to origin for later
226 merge.
227 lvconvert --splitmirrors Number --trackchanges LV_cache_raid1
229 [ COMMON_OPTIONS ]
230 [ PV ... ]
231 -
232 Merge LV images that were split from a raid1 LV.
234 lvconvert --mergemirrors VG|LV_linear_raid|Tag ...
236 [ COMMON_OPTIONS ]
237 -
238 Convert LV to a thin LV, using the original LV as an external origin.
240 lvconvert --type thin --thinpool LV LV_linear_striped_thin_cache_raid
242 [ -T|--thin ]
243 [ -r|--readahead auto|none|Number ]
244 [ -c|--chunksize Size[k|UNIT] ]
245 [ -Z|--zero y|n ]
246 [ --originname LV_new ]
247 [ --poolmetadata LV ]
248 [ --poolmetadatasize Size[m|UNIT] ]
249 [ --poolmetadataspare y|n ]
250 [ --metadataprofile String ]
251 [ COMMON_OPTIONS ]
252 -
253 Attach a cache pool to an LV, converts the LV to type cache.
255 lvconvert --type cache --cachepool LV LV_linear_striped_thin‐
257 pool_vdo_vdopool_vdopooldata_raid
258 [ -H|--cache ]
259 [ -Z|--zero y|n ]
260 [ -r|--readahead auto|none|Number ]
261 [ -c|--chunksize Size[k|UNIT] ]
262 [ --cachemetadataformat auto|1|2 ]
263 [ --cachemode writethrough|writeback|passthrough ]
264 [ --cachepolicy String ]
265 [ --cachesettings String ]
266 [ --poolmetadata LV ]
267 [ --poolmetadatasize Size[m|UNIT] ]
268 [ --poolmetadataspare y|n ]
269 [ --metadataprofile String ]
270 [ COMMON_OPTIONS ]
271 -
272 Attach a writecache to an LV, converts the LV to type writecache.
274 lvconvert --type writecache --cachevol LV LV_linear_striped_raid
276 [ --cachesettings String ]
277 [ COMMON_OPTIONS ]
278 -
279 Attach a cache to an LV, converts the LV to type cache.
281 lvconvert --type cache --cachevol LV LV_linear_striped_thinpool_raid
283 [ -H|--cache ]
284 [ -Z|--zero y|n ]
285 [ -c|--chunksize Size[k|UNIT] ]
286 [ --cachemetadataformat auto|1|2 ]
287 [ --cachemode writethrough|writeback|passthrough ]
288 [ --cachepolicy String ]
289 [ --cachesettings String ]
290 [ --poolmetadatasize Size[m|UNIT] ]
291 [ COMMON_OPTIONS ]
292 -
293 Add a writecache to an LV, using a specified cache device.
295 lvconvert --type writecache --cachedevice PV LV_linear_striped_raid
297 [ --cachesize Size[m|UNIT] ]
298 [ --cachesettings String ]
299 [ COMMON_OPTIONS ]
300 -
301 Add a cache to an LV, using a specified cache device.
303 lvconvert --type cache --cachedevice PV LV_linear_striped_thinpool_raid
305 [ --cachesize Size[m|UNIT] ]
306 [ --cachesettings String ]
307 [ COMMON_OPTIONS ]
308 -
309 Convert LV to type thin-pool.
311 lvconvert --type thin-pool LV_linear_striped_cache_raid
313 [ -I|--stripesize Size[k|UNIT] ]
314 [ -r|--readahead auto|none|Number ]
315 [ -c|--chunksize Size[k|UNIT] ]
316 [ -Z|--zero y|n ]
317 [ --stripes Number ]
318 [ --discards passdown|nopassdown|ignore ]
319 [ --poolmetadata LV ]
320 [ --poolmetadatasize Size[m|UNIT] ]
321 [ --poolmetadataspare y|n ]
322 [ --metadataprofile String ]
323 [ COMMON_OPTIONS ]
324 [ PV ... ]
325 -
326 Convert LV to type cache-pool.
328 lvconvert --type cache-pool LV_linear_striped_raid
330 [ -Z|--zero y|n ]
331 [ -r|--readahead auto|none|Number ]
332 [ -c|--chunksize Size[k|UNIT] ]
333 [ --cachemetadataformat auto|1|2 ]
334 [ --cachemode writethrough|writeback|passthrough ]
335 [ --cachepolicy String ]
336 [ --cachesettings String ]
337 [ --poolmetadata LV ]
338 [ --poolmetadatasize Size[m|UNIT] ]
339 [ --poolmetadataspare y|n ]
340 [ --metadataprofile String ]
341 [ COMMON_OPTIONS ]
342 [ PV ... ]
343 -
344 Convert LV to type vdopool.
346 lvconvert --type vdo-pool LV_linear_striped_cache_raid
348 [ -n|--name LV_new ]
349 [ -V|--virtualsize Size[m|UNIT] ]
350 [ --compression y|n ]
351 [ --deduplication y|n ]
352 [ COMMON_OPTIONS ]
353 -
354 Detach a cache from an LV.
356 lvconvert --splitcache LV_thinpool_cache_cachepool_vdopool_writecache
358 [ COMMON_OPTIONS ]
359 -
360 Merge thin LV into its origin LV.
362 lvconvert --mergethin LV_thin ...
364 [ COMMON_OPTIONS ]
365 -
366 Merge COW snapshot LV into its origin.
368 lvconvert --mergesnapshot LV_snapshot ...
370 [ -i|--interval Number ]
371 [ COMMON_OPTIONS ]
372 -
373 Combine a former COW snapshot (second arg) with a former
375 origin LV (first arg) to reverse a splitsnapshot command.
376 lvconvert --type snapshot LV LV_linear_striped
378 [ -s|--snapshot ]
379 [ -c|--chunksize Size[k|UNIT] ]
380 [ -Z|--zero y|n ]
381 [ COMMON_OPTIONS ]
382 -
383 Replace failed PVs in a raid or mirror LV.
385 Repair a thin pool.
386 Repair a cache pool.
387 lvconvert --repair LV_thinpool_cache_cachepool_mirror_raid
389 [ -i|--interval Number ]
390 [ --usepolicies ]
391 [ --poolmetadataspare y|n ]
392 [ COMMON_OPTIONS ]
393 [ PV ... ]
394 -
395 Replace specific PV(s) in a raid LV with another PV.
397 lvconvert --replace PV LV_raid
399 [ COMMON_OPTIONS ]
400 [ PV ... ]
401 -
402 Poll LV to continue conversion.
404 lvconvert --startpoll LV_mirror_raid
406 [ COMMON_OPTIONS ]
407 -
408 Add or remove data integrity checksums to raid images.
410 lvconvert --raidintegrity y|n LV_raid
412 [ --raidintegritymode String ]
413 [ --raidintegrityblocksize Number ]
414 [ COMMON_OPTIONS ]
415 [ PV ... ]
416 -
417 Common options for command:
419 [ -b|--background ]
420 [ -f|--force ]
421 [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit
422 ]
423 [ --noudevsync ]
424 Common options for lvm:
426 [ -d|--debug ]
427 [ -h|--help ]
428 [ -q|--quiet ]
429 [ -t|--test ]
430 [ -v|--verbose ]
431 [ -y|--yes ]
432 [ --commandprofile String ]
433 [ --config String ]
434 [ --driverloaded y|n ]
435 [ --lockopt String ]
436 [ --longhelp ]
437 [ --nolocking ]
438 [ --profile String ]
439 [ --version ]
440
442 --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit
443 Determines the allocation policy when a command needs to allo‐
444 cate Physical Extents (PEs) from the VG. Each VG and LV has an
445 allocation policy which can be changed with vgchange/lvchange,
446 or overriden on the command line. normal applies common sense
447 rules such as not placing parallel stripes on the same PV.
448 inherit applies the VG policy to an LV. contiguous requires new
449 PEs be placed adjacent to existing PEs. cling places new PEs on
450 the same PV as existing PEs in the same stripe of the LV. If
451 there are sufficient PEs for an allocation, but normal does not
452 use them, anywhere will use them even if it reduces performance,
453 e.g. by placing two stripes on the same PV. Optional positional
454 PV args on the command line can also be used to limit which PVs
455 the command will use for allocation. See lvm(8) for more infor‐
456 mation about allocation.
457 -b|--background
459 If the operation requires polling, this option causes the com‐
460 mand to return before the operation is complete, and polling is
461 done in the background.
462 -H|--cache
464 Specifies the command is handling a cache LV or cache pool. See
465 --type cache and --type cache-pool. See lvmcache(7) for more
466 information about LVM caching.
467 --cachedevice PV
469 The name of a device to use for a cache.
470 --cachemetadataformat auto|1|2
472 Specifies the cache metadata format used by cache target.
473 --cachemode writethrough|writeback|passthrough
475 Specifies when writes to a cache LV should be considered com‐
476 plete. writeback considers a write complete as soon as it is
477 stored in the cache pool. writethough considers a write com‐
478 plete only when it has been stored in both the cache pool and on
479 the origin LV. While writethrough may be slower for writes, it
480 is more resilient if something should happen to a device associ‐
481 ated with the cache pool LV. With passthrough, all reads are
482 served from the origin LV (all reads miss the cache) and all
483 writes are forwarded to the origin LV; additionally, write hits
484 cause cache block invalidates. See lvmcache(7) for more informa‐
485 tion.
486 --cachepolicy String
488 Specifies the cache policy for a cache LV. See lvmcache(7) for
489 more information.
490 --cachepool LV
492 The name of a cache pool.
493 --cachesettings String
495 Specifies tunable values for a cache LV in "Key = Value" form.
496 Repeat this option to specify multiple values. (The default
497 values should usually be adequate.) The special string value
498 default switches settings back to their default kernel values
499 and removes them from the list of settings stored in LVM meta‐
500 data. See lvmcache(7) for more information.
501 --cachesize Size[m|UNIT]
503 The size of cache to use.
504 --cachevol LV
506 The name of a cache volume.
507 -c|--chunksize Size[k|UNIT]
509 The size of chunks in a snapshot, cache pool or thin pool. For
510 snapshots, the value must be a power of 2 between 4KiB and
511 512KiB and the default value is 4. For a cache pool the value
512 must be between 32KiB and 1GiB and the default value is 64. For
513 a thin pool the value must be between 64KiB and 1GiB and the
514 default value starts with 64 and scales up to fit the pool meta‐
515 data size within 128MiB, if the pool metadata size is not speci‐
516 fied. The value must be a multiple of 64KiB. See lvmthin(7)
517 and lvmcache(7) for more information.
518 --commandprofile String
520 The command profile to use for command configuration. See
521 lvm.conf(5) for more information about profiles.
522 --compression y|n
524 Controls whether compression is enabled or disable for VDO vol‐
525 ume. See lvmvdo(7) for more information about VDO usage.
526 --config String
528 Config settings for the command. These override lvm.conf set‐
529 tings. The String arg uses the same format as lvm.conf, or may
530 use section/field syntax. See lvm.conf(5) for more information
531 about config.
532 -d|--debug ...
534 Set debug level. Repeat from 1 to 6 times to increase the detail
535 of messages sent to the log file and/or syslog (if configured).
536 --deduplication y|n
538 Controls whether deduplication is enabled or disable for VDO
539 volume. See lvmvdo(7) for more information about VDO usage.
540 --discards passdown|nopassdown|ignore
542 Specifies how the device-mapper thin pool layer in the kernel
543 should handle discards. ignore causes the thin pool to ignore
544 discards. nopassdown causes the thin pool to process discards
545 itself to allow reuse of unneeded extents in the thin pool.
546 passdown causes the thin pool to process discards itself (like
547 nopassdown) and pass the discards to the underlying device. See
548 lvmthin(7) for more information.
549 --driverloaded y|n
551 If set to no, the command will not attempt to use device-mapper.
552 For testing and debugging.
553 -f|--force ...
555 Override various checks, confirmations and protections. Use
556 with extreme caution.
557 -h|--help
559 Display help text.
560 -i|--interval Number
562 Report progress at regular intervals.
563 --lockopt String
565 Used to pass options for special cases to lvmlockd. See lvm‐
566 lockd(8) for more information.
567 --longhelp
569 Display long help text.
570 --merge
572 An alias for --mergethin, --mergemirrors, or --mergesnapshot,
573 depending on the type of LV.
574 --mergemirrors
576 Merge LV images that were split from a raid1 LV. See --split‐
577 mirrors with --trackchanges.
578 --mergesnapshot
580 Merge COW snapshot LV into its origin. When merging a snapshot,
581 if both the origin and snapshot LVs are not open, the merge will
582 start immediately. Otherwise, the merge will start the first
583 time either the origin or snapshot LV are activated and both are
584 closed. Merging a snapshot into an origin that cannot be closed,
585 for example a root filesystem, is deferred until the next time
586 the origin volume is activated. When merging starts, the result‐
587 ing LV will have the origin's name, minor number and UUID. While
588 the merge is in progress, reads or writes to the origin appear
589 as being directed to the snapshot being merged. When the merge
590 finishes, the merged snapshot is removed. Multiple snapshots
591 may be specified on the command line or a @tag may be used to
592 specify multiple snapshots be merged to their respective origin.
593 --mergethin
595 Merge thin LV into its origin LV. The origin thin LV takes the
596 content of the thin snapshot, and the thin snapshot LV is
597 removed. See lvmthin(7) for more information.
598 --metadataprofile String
600 The metadata profile to use for command configuration. See
601 lvm.conf(5) for more information about profiles.
602 --mirrorlog core|disk
604 Specifies the type of mirror log for LVs with the "mirror" type
605 (does not apply to the "raid1" type.) disk is a persistent log
606 and requires a small amount of storage space, usually on a sepa‐
607 rate device from the data being mirrored. core is not persis‐
608 tent; the log is kept only in memory. In this case, the mirror
609 must be synchronized (by copying LV data from the first device
610 to others) each time the LV is activated, e.g. after reboot.
611 mirrored is a persistent log that is itself mirrored, but should
612 be avoided. Instead, use the raid1 type for log redundancy.
613 -m|--mirrors [+|-]Number
615 Specifies the number of mirror images in addition to the origi‐
616 nal LV image, e.g. --mirrors 1 means there are two images of the
617 data, the original and one mirror image. Optional positional PV
618 args on the command line can specify the devices the images
619 should be placed on. There are two mirroring implementations:
620 "raid1" and "mirror". These are the names of the corresponding
621 LV types, or "segment types". Use the --type option to specify
622 which to use (raid1 is default, and mirror is legacy) Use
623 lvm.conf global/mirror_segtype_default and global/raid10_seg‐
624 type_default to configure the default types. The plus prefix +
625 can be used, in which case the number is added to the current
626 number of images, or the minus prefix - can be used, in which
627 case the number is subtracted from the current number of images.
628 See lvmraid(7) for more information.
629 -n|--name String
631 Specifies the name of a new LV. When unspecified, a default
632 name of "lvol#" is generated, where # is a number generated by
633 LVM.
634 --nolocking
636 Disable locking.
637 --noudevsync
639 Disables udev synchronisation. The process will not wait for
640 notification from udev. It will continue irrespective of any
641 possible udev processing in the background. Only use this if
642 udev is not running or has rules that ignore the devices LVM
643 creates.
644 --originname LV
646 Specifies the name to use for the external origin LV when con‐
647 verting an LV to a thin LV. The LV being converted becomes a
648 read-only external origin with this name.
649 --poolmetadata LV
651 The name of a an LV to use for storing pool metadata.
652 --poolmetadatasize Size[m|UNIT]
654 Specifies the size of the new pool metadata LV.
655 --poolmetadataspare y|n
657 Enable or disable the automatic creation and management of a
658 spare pool metadata LV in the VG. A spare metadata LV is
659 reserved space that can be used when repairing a pool.
660 --profile String
662 An alias for --commandprofile or --metadataprofile, depending on
663 the command.
664 -q|--quiet ...
666 Suppress output and log messages. Overrides --debug and --ver‐
667 bose. Repeat once to also suppress any prompts with answer
668 'no'.
669 --raidintegrity y|n
671 Enable or disable data integrity checksums for raid images.
672 --raidintegrityblocksize Number
674 The block size to use for dm-integrity on raid images. The
675 integrity block size should usually match the device logical
676 block size, or the file system block size. It may be less than
677 the file system block size, but not less than the device logical
678 block size. Possible values: 512, 1024, 2048, 4096.
679 --raidintegritymode String
681 Use a journal (default) or bitmap for keeping integrity check‐
682 sums consistent in case of a crash. The bitmap areas are recal‐
683 culated after a crash, so corruption in those areas would not be
684 detected. A journal does not have this problem. The journal
685 mode doubles writes to storage, but can improve performance for
686 scattered writes packed into a single journal write. bitmap
687 mode can in theory achieve full write throughput of the device,
688 but would not benefit from the potential scattered write opti‐
689 mization.
690 -r|--readahead auto|none|Number
692 Sets read ahead sector count of an LV. auto is the default
693 which allows the kernel to choose a suitable value automati‐
694 cally. none is equivalent to zero.
695 -R|--regionsize Size[m|UNIT]
697 Size of each raid or mirror synchronization region. lvm.conf
698 activation/raid_region_size can be used to configure a default.
699 --repair
701 Replace failed PVs in a raid or mirror LV, or run a repair util‐
702 ity on a thin pool. See lvmraid(7) and lvmthin(7) for more
703 information.
704 --replace PV
706 Replace a specific PV in a raid LV with another PV. The new PV
707 to use can be optionally specified after the LV. Multiple PVs
708 can be replaced by repeating this option. See lvmraid(7) for
709 more information.
710 -s|--snapshot
712 Combine a former COW snapshot LV with a former origin LV to
713 reverse a previous --splitsnapshot command.
714 --splitcache
716 Separates a cache pool from a cache LV, and keeps the unused
717 cache pool LV. Before the separation, the cache is flushed.
718 Also see --uncache.
719 --splitmirrors Number
721 Splits the specified number of images from a raid1 or mirror LV
722 and uses them to create a new LV. If --trackchanges is also
723 specified, changes to the raid1 LV are tracked while the split
724 LV remains detached. If --name is specified, then the images
725 are permanently split from the original LV and changes are not
726 tracked.
727 --splitsnapshot
729 Separates a COW snapshot from its origin LV. The LV that is
730 split off contains the chunks that differ from the origin LV
731 along with metadata describing them. This LV can be wiped and
732 then destroyed with lvremove.
733 --startpoll
735 Start polling an LV to continue processing a conversion.
736 --stripes Number
738 Specifies the number of stripes in a striped LV. This is the
739 number of PVs (devices) that a striped LV is spread across. Data
740 that appears sequential in the LV is spread across multiple
741 devices in units of the stripe size (see --stripesize). This
742 does not apply to existing allocated space, only newly allocated
743 space can be striped.
744 -I|--stripesize Size[k|UNIT]
746 The amount of data that is written to one device before moving
747 to the next in a striped LV.
748 --swapmetadata
750 Extracts the metadata LV from a pool and replaces it with
751 another specified LV. The extracted LV is preserved and given
752 the name of the LV that replaced it. Use for repair only. When
753 the metadata LV is swapped out of the pool, it can be activated
754 directly and used with thin provisioning tools: cache_dump(8),
755 cache_repair(8), cache_restore(8), thin_dump(8), thin_repair(8),
756 thin_restore(8).
757 -t|--test
759 Run in test mode. Commands will not update metadata. This is
760 implemented by disabling all metadata writing but nevertheless
761 returning success to the calling function. This may lead to
762 unusual error messages in multi-stage operations if a tool
763 relies on reading back metadata it believes has changed but
764 hasn't.
765 -T|--thin
767 Specifies the command is handling a thin LV or thin pool. See
768 --type thin, --type thin-pool, and --virtualsize. See
769 lvmthin(7) for more information about LVM thin provisioning.
770 --thinpool LV
772 The name of a thin pool LV.
773 --trackchanges
775 Can be used with --splitmirrors on a raid1 LV. This causes
776 changes to the original raid1 LV to be tracked while the split
777 images remain detached. This is a temporary state that allows
778 the read-only detached image to be merged efficiently back into
779 the raid1 LV later. Only the regions with changed data are
780 resynchronized during merge. While a raid1 LV is tracking
781 changes, operations on it are limited to merging the split image
782 (see --mergemirrors) or permanently splitting the image (see
783 --splitmirrors with --name.
784 --type linear|striped|snapshot|mir‐
786 ror|raid|thin|cache|vdo|thin-pool|cache-pool|vdo-pool
787 The LV type, also known as "segment type" or "segtype". See
788 usage descriptions for the specific ways to use these types.
789 For more information about redundancy and performance (raid<N>,
790 mirror, striped, linear) see lvmraid(7). For thin provisioning
791 (thin, thin-pool) see lvmthin(7). For performance caching
792 (cache, cache-pool) see lvmcache(7). For copy-on-write snap‐
793 shots (snapshot) see usage definitions. For VDO (vdo) see
794 lvmvdo(7). Several commands omit an explicit type option
795 because the type is inferred from other options or shortcuts
796 (e.g. --stripes, --mirrors, --snapshot, --virtualsize, --thin,
797 --cache, --vdo). Use inferred types with care because it can
798 lead to unexpected results.
799 --uncache
801 Separates a cache pool from a cache LV, and deletes the unused
802 cache pool LV. Before the separation, the cache is flushed.
803 Also see --splitcache.
804 --usepolicies
806 Perform an operation according to the policy configured in
807 lvm.conf or a profile.
808 --vdopool LV
810 The name of a VDO pool LV. See lvmvdo(7) for more information
811 about VDO usage.
812 -v|--verbose ...
814 Set verbose level. Repeat from 1 to 4 times to increase the
815 detail of messages sent to stdout and stderr.
816 --version
818 Display version information.
819 -V|--virtualsize Size[m|UNIT]
821 The virtual size of a new thin LV. See lvmthin(7) for more
822 information about LVM thin provisioning. Using virtual size
823 (-V) and actual size (-L) together creates a sparse LV.
824 lvm.conf global/sparse_segtype_default determines the default
825 segment type used to create a sparse LV. Anything written to a
826 sparse LV will be returned when reading from it. Reading from
827 other areas of the LV will return blocks of zeros. When using a
828 snapshot to create a sparse LV, a hidden virtual device is cre‐
829 ated using the zero target, and the LV has the suffix _vorigin.
830 Snapshots are less efficient than thin provisioning when creat‐
831 ing large sparse LVs (GiB).
832 -y|--yes
834 Do not prompt for confirmation interactively but always assume
835 the answer yes. Use with extreme caution. (For automatic no,
836 see -qq.)
837 -Z|--zero y|n
839 For snapshots, this controls zeroing of the first 4KiB of data
840 in the snapshot. If the LV is read-only, the snapshot will not
841 be zeroed. For thin pools, this controls zeroing of provisioned
842 blocks. Provisioning of large zeroed chunks negatively impacts
843 performance.
844
846 VG
847 Volume Group name. See lvm(8) for valid names.
848 LV
850 Logical Volume name. See lvm(8) for valid names. An LV posi‐
851 tional arg generally includes the VG name and LV name, e.g.
852 VG/LV. LV followed by _<type> indicates that an LV of the given
853 type is required. (raid represents raid<N> type)
854 PV
856 Physical Volume name, a device path under /dev. For commands
857 managing physical extents, a PV positional arg generally accepts
858 a suffix indicating a range (or multiple ranges) of physical
859 extents (PEs). When the first PE is omitted, it defaults to the
860 start of the device, and when the last PE is omitted it defaults
861 to end. Start and end range (inclusive): PV[:PE-PE]... Start
862 and length range (counting from 0): PV[:PE+PE]...
863 Tag
865 Tag name. See lvm(8) for information about tag names and using
866 tags in place of a VG, LV or PV.
867 String
869 See the option description for information about the string con‐
870 tent.
871 Size[UNIT]
873 Size is an input number that accepts an optional unit. Input
874 units are always treated as base two values, regardless of capi‐
875 talization, e.g. 'k' and 'K' both refer to 1024. The default
876 input unit is specified by letter, followed by |UNIT. UNIT rep‐
877 resents other possible input units: bBsSkKmMgGtTpPeE. b|B is
878 bytes, s|S is sectors of 512 bytes, k|K is kilobytes, m|M is
879 megabytes, g|G is gigabytes, t|T is terabytes, p|P is petabytes,
880 e|E is exabytes. (This should not be confused with the output
881 control --units, where capital letters mean multiple of 1000.)
882
884 See lvm(8) for information about environment variables used by lvm.
885 For example, LVM_VG_NAME can generally be substituted for a required VG
886 parameter.
887
889 Alternate command forms, advanced command usage, and listing of all
890 valid syntax for completeness.
891 Change the region size of an LV.
893 lvconvert -R|--regionsize Size[m|UNIT] LV_raid
895 [ COMMON_OPTIONS ]
896 -
897 Change the type of mirror log used by a mirror LV.
899 lvconvert --mirrorlog core|disk LV_mirror
901 [ COMMON_OPTIONS ]
902 [ PV ... ]
903 -
904 Convert LV to a thin LV, using the original LV as an external origin
906 (infers --type thin).
907 lvconvert -T|--thin --thinpool LV LV_linear_striped_thin_cache_raid
909 [ -r|--readahead auto|none|Number ]
910 [ -c|--chunksize Size[k|UNIT] ]
911 [ -Z|--zero y|n ]
912 [ --type thin ]
913 [ --originname LV_new ]
914 [ --poolmetadata LV ]
915 [ --poolmetadatasize Size[m|UNIT] ]
916 [ --poolmetadataspare y|n ]
917 [ --metadataprofile String ]
918 [ COMMON_OPTIONS ]
919 -
920 Attach a cache pool to an LV (infers --type cache).
922 lvconvert -H|--cache --cachepool LV LV_linear_striped_thin‐
924 pool_vdo_vdopool_vdopooldata_raid
925 [ -Z|--zero y|n ]
926 [ -r|--readahead auto|none|Number ]
927 [ -c|--chunksize Size[k|UNIT] ]
928 [ --type cache ]
929 [ --cachemetadataformat auto|1|2 ]
930 [ --cachemode writethrough|writeback|passthrough ]
931 [ --cachepolicy String ]
932 [ --cachesettings String ]
933 [ --poolmetadata LV ]
934 [ --poolmetadatasize Size[m|UNIT] ]
935 [ --poolmetadataspare y|n ]
936 [ --metadataprofile String ]
937 [ COMMON_OPTIONS ]
938 -
939 Attach a cache to an LV, converts the LV to type cache.
941 lvconvert -H|--cache --cachevol LV LV_linear_striped_thinpool_raid
943 [ -Z|--zero y|n ]
944 [ -c|--chunksize Size[k|UNIT] ]
945 [ --cachemetadataformat auto|1|2 ]
946 [ --cachemode writethrough|writeback|passthrough ]
947 [ --cachepolicy String ]
948 [ --cachesettings String ]
949 [ --poolmetadatasize Size[m|UNIT] ]
950 [ COMMON_OPTIONS ]
951 -
952 Convert LV to type vdopool.
954 lvconvert --vdopool LV_linear_striped_cache_raid
956 [ -n|--name LV_new ]
957 [ -V|--virtualsize Size[m|UNIT] ]
958 [ --type vdo-pool ]
959 [ --compression y|n ]
960 [ --deduplication y|n ]
961 [ COMMON_OPTIONS ]
962 -
963 Detach and delete a cache from an LV.
965 lvconvert --uncache LV_thinpool_cache_vdopool_writecache
967 [ COMMON_OPTIONS ]
968 -
969 Swap metadata LV in a thin pool or cache pool (for repair only).
971 lvconvert --swapmetadata --poolmetadata LV LV_thinpool_cachepool
973 [ -c|--chunksize Size[k|UNIT] ]
974 [ COMMON_OPTIONS ]
975 -
976 Merge LV that was split from a mirror (variant, use --mergemirrors).
978 Merge thin LV into its origin LV (variant, use --mergethin).
979 Merge COW snapshot LV into its origin (variant, use --mergesnapshot).
980 lvconvert --merge VG|LV_linear_striped_snapshot_thin_raid|Tag ...
982 [ -i|--interval Number ]
983 [ COMMON_OPTIONS ]
984 -
985 Separate a COW snapshot from its origin LV.
987 lvconvert --splitsnapshot LV_snapshot
989 [ COMMON_OPTIONS ]
990 -
991 Combine a former COW snapshot (second arg) with a former
993 origin LV (first arg) to reverse a splitsnapshot command.
994 lvconvert -s|--snapshot LV LV_linear_striped
996 [ -c|--chunksize Size[k|UNIT] ]
997 [ -Z|--zero y|n ]
998 [ --type snapshot ]
999 [ COMMON_OPTIONS ]
1000 -
1001 Poll LV to continue conversion (also see --startpoll)
1003 or waits till conversion/mirror syncing is finished
1004 lvconvert LV_mirror_raid
1006 [ COMMON_OPTIONS ]
1007 -
1008
1011 This previous command syntax would perform two different operations:
1012 lvconvert --thinpool LV1 --poolmetadata LV2
1013 If LV1 was not a thin pool, the command would convert LV1 to a thin
1014 pool, optionally using a specified LV for metadata. But, if LV1 was
1015 already a thin pool, the command would swap the current metadata LV
1016 with LV2 (for repair purposes.)
1017 In the same way, this previous command syntax would perform two differ‐
1019 ent operations:
1020 lvconvert --cachepool LV1 --poolmetadata LV2
1021 If LV1 was not a cache pool, the command would convert LV1 to a cache
1022 pool, optionally using a specified LV for metadata. But, if LV1 was
1023 already a cache pool, the command would swap the current metadata LV
1024 with LV2 (for repair purposes.)
1025
1027 Convert a linear LV to a two-way mirror LV.
1028 lvconvert --type mirror --mirrors 1 vg/lvol1
1029 Convert a linear LV to a two-way RAID1 LV.
1031 lvconvert --type raid1 --mirrors 1 vg/lvol1
1032 Convert a mirror LV to use an in-memory log.
1034 lvconvert --mirrorlog core vg/lvol1
1035 Convert a mirror LV to use a disk log.
1037 lvconvert --mirrorlog disk vg/lvol1
1038 Convert a mirror or raid1 LV to a linear LV.
1040 lvconvert --type linear vg/lvol1
1041 Convert a mirror LV to a raid1 LV with the same number of images.
1043 lvconvert --type raid1 vg/lvol1
1044 Convert a linear LV to a two-way mirror LV, allocating new extents from
1046 specific PV ranges.
1047 lvconvert --mirrors 1 vg/lvol1 /dev/sda:0-15 /dev/sdb:0-15
1048 Convert a mirror LV to a linear LV, freeing physical extents from a
1050 specific PV.
1051 lvconvert --type linear vg/lvol1 /dev/sda
1052 Split one image from a mirror or raid1 LV, making it a new LV.
1054 lvconvert --splitmirrors 1 --name lv_split vg/lvol1
1055 Split one image from a raid1 LV, and track changes made to the raid1 LV
1057 while the split image remains detached.
1058 lvconvert --splitmirrors 1 --trackchanges vg/lvol1
1059 Merge an image (that was previously created with --splitmirrors and
1061 --trackchanges) back into the original raid1 LV.
1062 lvconvert --mergemirrors vg/lvol1_rimage_1
1063 Replace PV /dev/sdb1 with PV /dev/sdf1 in a raid1/4/5/6/10 LV.
1065 lvconvert --replace /dev/sdb1 vg/lvol1 /dev/sdf1
1066 Replace 3 PVs /dev/sd[b-d]1 with PVs /dev/sd[f-h]1 in a raid1 LV.
1068 lvconvert --replace /dev/sdb1 --replace /dev/sdc1 --replace /dev/sdd1
1069 vg/lvol1 /dev/sd[fgh]1
1070 Replace the maximum of 2 PVs /dev/sd[bc]1 with PVs /dev/sd[gh]1 in a
1072 raid6 LV.
1073 lvconvert --replace /dev/sdb1 --replace /dev/sdc1 vg/lvol1 /dev/sd[gh]1
1074 Convert an LV into a thin LV in the specified thin pool. The existing
1076 LV is used as an external read-only origin for the new thin LV.
1077 lvconvert --type thin --thinpool vg/tpool1 vg/lvol1
1078 Convert an LV into a thin LV in the specified thin pool. The existing
1080 LV is used as an external read-only origin for the new thin LV, and is
1081 renamed "external".
1082 lvconvert --type thin --thinpool vg/tpool1
1083 --originname external vg/lvol1
1084 Convert an LV to a cache pool LV using another specified LV for cache
1086 pool metadata.
1087 lvconvert --type cache-pool --poolmetadata vg/poolmeta1 vg/lvol1
1088 Convert an LV to a cache LV using the specified cache pool and chunk
1090 size.
1091 lvconvert --type cache --cachepool vg/cpool1 -c 128 vg/lvol1
1092 Detach and keep the cache pool from a cache LV.
1094 lvconvert --splitcache vg/lvol1
1095 Detach and remove the cache pool from a cache LV.
1097 lvconvert --uncache vg/lvol1
1098
1100 lvm(8) lvm.conf(5) lvmconfig(8)
1101 pvchange(8) pvck(8) pvcreate(8) pvdisplay(8) pvmove(8) pvremove(8)
1103 pvresize(8) pvs(8) pvscan(8)
1104 vgcfgbackup(8) vgcfgrestore(8) vgchange(8) vgck(8) vgcreate(8) vgcon‐
1106 vert(8) vgdisplay(8) vgexport(8) vgextend(8) vgimport(8) vgimport‐
1107 clone(8) vgmerge(8) vgmknodes(8) vgreduce(8) vgremove(8) vgrename(8)
1108 vgs(8) vgscan(8) vgsplit(8)
1109 lvcreate(8) lvchange(8) lvconvert(8) lvdisplay(8) lvextend(8) lvre‐
1111 duce(8) lvremove(8) lvrename(8) lvresize(8) lvs(8) lvscan(8)
1112 lvm-fullreport(8) lvm-lvpoll(8) lvm2-activation-generator(8) blkdeacti‐
1114 vate(8) lvmdump(8)
1115 dmeventd(8) lvmpolld(8) lvmlockd(8) lvmlockctl(8) cmirrord(8) lvmd‐
1117 busd(8)
1118 lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)
1120Red Hat, Inc. LVM TOOLS 2.03.10(2) (2020-08-09) LVCONVERT(8)