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# This is an example configuration file for the LVM2 system.

# It contains the default settings that would be used if there was no

# /etc/lvm/lvm.conf file.

#

# Refer to 'man lvm.conf' for further information including the file layout.

#

# Refer to 'man lvm.conf' for information about how settings configured in

# this file are combined with built-in values and command line options to

# arrive at the final values used by LVM.

#

# Refer to 'man lvmconfig' for information about displaying the built-in

# and configured values used by LVM.

#

# If a default value is set in this file (not commented out), then a

# new version of LVM using this file will continue using that value,

# even if the new version of LVM changes the built-in default value.

#

# To put this file in a different directory and override /etc/lvm set

# the environment variable LVM_SYSTEM_DIR before running the tools.

#

# N.B. Take care that each setting only appears once if uncommenting

# example settings in this file.

# Configuration section config.

# How LVM configuration settings are handled.

config {

	# Configuration option config/checks.

	# If enabled, any LVM configuration mismatch is reported.

	# This implies checking that the configuration key is understood by

	# LVM and that the value of the key is the proper type. If disabled,

	# any configuration mismatch is ignored and the default value is used

	# without any warning (a message about the configuration key not being

	# found is issued in verbose mode only).

	checks = 1

	# Configuration option config/abort_on_errors.

	# Abort the LVM process if a configuration mismatch is found.

	abort_on_errors = 0

	# Configuration option config/profile_dir.

	# Directory where LVM looks for configuration profiles.

	profile_dir = "/etc/lvm/profile"

}

# Configuration section devices.

# How LVM uses block devices.

devices {

	# Configuration option devices/dir.

	# Directory in which to create volume group device nodes.

	# Commands also accept this as a prefix on volume group names.

	# This configuration option is advanced.

	dir = "/dev"

	# Configuration option devices/scan.

	# Directories containing device nodes to use with LVM.

	# This configuration option is advanced.

	scan = [ "/dev" ]

	# Configuration option devices/obtain_device_list_from_udev.

	# Obtain the list of available devices from udev.

	# This avoids opening or using any inapplicable non-block devices or

	# subdirectories found in the udev directory. Any device node or

	# symlink not managed by udev in the udev directory is ignored. This

	# setting applies only to the udev-managed device directory; other

	# directories will be scanned fully. LVM needs to be compiled with

	# udev support for this setting to apply.

	obtain_device_list_from_udev = 1

	# Configuration option devices/external_device_info_source.

	# Select an external device information source.

	# Some information may already be available in the system and LVM can

	# use this information to determine the exact type or use of devices it

	# processes. Using an existing external device information source can

	# speed up device processing as LVM does not need to run its own native

	# routines to acquire this information. For example, this information

	# is used to drive LVM filtering like MD component detection, multipath

	# component detection, partition detection and others.

	#

	# Accepted values:

	#   none

	#     No external device information source is used.

	#   udev

	#     Reuse existing udev database records. Applicable only if LVM is

	#     compiled with udev support.

	#

	external_device_info_source = "none"

	# Configuration option devices/hints.

	# Use a local file to remember which devices have PVs on them.

	# Some commands will use this as an optimization to reduce device

	# scanning, and will only scan the listed PVs. Removing the hint file

	# will cause lvm to generate a new one. Disable hints if PVs will

	# be copied onto devices using non-lvm commands, like dd.

	#

	# Accepted values:

	#   all

	#     Use all hints.

	#   none

	#     Use no hints.

	#

	# This configuration option has an automatic default value.

	# hints = "all"

	# Configuration option devices/preferred_names.

	# Select which path name to display for a block device.

	# If multiple path names exist for a block device, and LVM needs to

	# display a name for the device, the path names are matched against

	# each item in this list of regular expressions. The first match is

	# used. Try to avoid using undescriptive /dev/dm-N names, if present.

	# If no preferred name matches, or if preferred_names are not defined,

	# the following built-in preferences are applied in order until one

	# produces a preferred name:

	# Prefer names with path prefixes in the order of:

	# /dev/mapper, /dev/disk, /dev/dm-*, /dev/block.

	# Prefer the name with the least number of slashes.

	# Prefer a name that is a symlink.

	# Prefer the path with least value in lexicographical order.

	#

	# Example

	# preferred_names = [ "^/dev/mpath/", "^/dev/mapper/mpath", "^/dev/[hs]d" ]

	#

	# This configuration option has an automatic default value.

	# preferred_names = [ "^/dev/mpath/", "^/dev/mapper/mpath", "^/dev/[hs]d" ]

	# Configuration option devices/use_devicesfile.

	# Enable or disable the use of a devices file.

	# When enabled, lvm will only use devices that

	# are lised in the devices file. A devices file will

	# be used, regardless of this setting, when the --devicesfile

	# option is set to a specific file name.

	# This configuration option has an automatic default value.

	# use_devicesfile = 0

	# Configuration option devices/devicesfile.

	# The name of the system devices file, listing devices that LVM should use.

	# This should not be used to select a non-system devices file.

	# The --devicesfile option is intended for alternative devices files.

	# This configuration option has an automatic default value.

	# devicesfile = "system.devices"

	# Configuration option devices/search_for_devnames.

	# Look outside of the devices file for missing devname entries.

	# A devname entry is used for a device that does not have a stable

	# device id, e.g. wwid, so the unstable device name is used as

	# the device id. After reboot, or if the device is reattached,

	# the device name may change, in which case lvm will not find

	# the expected PV on the device listed in the devices file.

	# This setting controls whether lvm will search other devices,

	# outside the devices file, to look for the missing PV on a

	# renamed device. If "none", lvm will not look at other devices,

	# and the PV may appear to be missing. If "auto", lvm will look

	# at other devices, but only those that are likely to have the PV.

	# If "all", lvm will look at all devices on the system.

	# This configuration option has an automatic default value.

	# search_for_devnames = "auto"

	# Configuration option devices/filter.

	# Limit the block devices that are used by LVM commands.

	# This is a list of regular expressions used to accept or reject block

	# device path names. Each regex is delimited by a vertical bar '|'

	# (or any character) and is preceded by 'a' to accept the path, or

	# by 'r' to reject the path. The first regex in the list to match the

	# path is used, producing the 'a' or 'r' result for the device.

	# When multiple path names exist for a block device, if any path name

	# matches an 'a' pattern before an 'r' pattern, then the device is

	# accepted. If all the path names match an 'r' pattern first, then the

	# device is rejected. Unmatching path names do not affect the accept

	# or reject decision. If no path names for a device match a pattern,

	# then the device is accepted. Be careful mixing 'a' and 'r' patterns,

	# as the combination might produce unexpected results (test changes.)

	# Run vgscan after changing the filter to regenerate the cache.

	#

	# Example

	# Accept every block device:

	# filter = [ "a|.*|" ]

	# Reject the cdrom drive:

	# filter = [ "r|/dev/cdrom|" ]

	# Work with just loopback devices, e.g. for testing:

	# filter = [ "a|loop|", "r|.*|" ]

	# Accept all loop devices and ide drives except hdc:

	# filter = [ "a|loop|", "r|/dev/hdc|", "a|/dev/ide|", "r|.*|" ]

	# Use anchors to be very specific:

	# filter = [ "a|^/dev/hda8$|", "r|.*|" ]

	#

	# This configuration option has an automatic default value.

	# filter = [ "a|.*|" ]

	# Configuration option devices/global_filter.

	# Limit the block devices that are used by LVM system components.

	# Because devices/filter may be overridden from the command line, it is

	# not suitable for system-wide device filtering, e.g. udev.

	# Use global_filter to hide devices from these LVM system components.

	# The syntax is the same as devices/filter. Devices rejected by

	# global_filter are not opened by LVM.

	# This configuration option has an automatic default value.

	# global_filter = [ "a|.*|" ]

	# Configuration option devices/types.

	# List of additional acceptable block device types.

	# These are of device type names from /proc/devices, followed by the

	# maximum number of partitions.

	#

	# Example

	# types = [ "fd", 16 ]

	#

	# This configuration option is advanced.

	# This configuration option does not have a default value defined.

	# Configuration option devices/sysfs_scan.

	# Restrict device scanning to block devices appearing in sysfs.

	# This is a quick way of filtering out block devices that are not

	# present on the system. sysfs must be part of the kernel and mounted.)

	sysfs_scan = 1

	# Configuration option devices/scan_lvs.

	# Scan LVM LVs for layered PVs, allowing LVs to be used as PVs.

	# When 1, LVM will detect PVs layered on LVs, and caution must be

	# taken to avoid a host accessing a layered VG that may not belong

	# to it, e.g. from a guest image. This generally requires excluding

	# the LVs with device filters. Also, when this setting is enabled,

	# every LVM command will scan every active LV on the system (unless

	# filtered), which can cause performance problems on systems with

	# many active LVs. When this setting is 0, LVM will not detect or

	# use PVs that exist on LVs, and will not allow a PV to be created on

	# an LV. The LVs are ignored using a built in device filter that

	# identifies and excludes LVs.

	scan_lvs = 0

	# Configuration option devices/multipath_component_detection.

	# Ignore devices that are components of DM multipath devices.

	multipath_component_detection = 1

	# Configuration option devices/md_component_detection.

	# Enable detection and exclusion of MD component devices.

	# An MD component device is a block device that MD uses as part

	# of a software RAID virtual device. When an LVM PV is created

	# on an MD device, LVM must only use the top level MD device as

	# the PV, and should ignore the underlying component devices.

	# In cases where the MD superblock is located at the end of the

	# component devices, it is more difficult for LVM to consistently

	# identify an MD component, see the md_component_checks setting.

	md_component_detection = 1

	# Configuration option devices/md_component_checks.

	# The checks LVM should use to detect MD component devices.

	# MD component devices are block devices used by MD software RAID.

	#

	# Accepted values:

	#   auto

	#     LVM will skip scanning the end of devices when it has other

	#     indications that the device is not an MD component.

	#   start

	#     LVM will only scan the start of devices for MD superblocks.

	#     This does not incur extra I/O by LVM.

	#   full

	#     LVM will scan the start and end of devices for MD superblocks.

	#     This requires an extra read at the end of devices.

	#

	# This configuration option has an automatic default value.

	# md_component_checks = "auto"

	# Configuration option devices/fw_raid_component_detection.

	# Ignore devices that are components of firmware RAID devices.

	# LVM must use an external_device_info_source other than none for this

	# detection to execute.

	fw_raid_component_detection = 0

	# Configuration option devices/md_chunk_alignment.

	# Align the start of a PV data area with md device's stripe-width.

	# This applies if a PV is placed directly on an md device.

	# default_data_alignment will be overridden if it is not aligned

	# with the value detected for this setting.

	# This setting is overridden by data_alignment_detection,

	# data_alignment, and the --dataalignment option.

	md_chunk_alignment = 1

	# Configuration option devices/default_data_alignment.

	# Align the start of a PV data area with this number of MiB.

	# Set to 1 for 1MiB, 2 for 2MiB, etc. Set to 0 to disable.

	# This setting is overridden by data_alignment and the --dataalignment

	# option.

	# This configuration option has an automatic default value.

	# default_data_alignment = 1

	# Configuration option devices/data_alignment_detection.

	# Align the start of a PV data area with sysfs io properties.

	# The start of a PV data area will be a multiple of minimum_io_size or

	# optimal_io_size exposed in sysfs. minimum_io_size is the smallest

	# request the device can perform without incurring a read-modify-write

	# penalty, e.g. MD chunk size. optimal_io_size is the device's

	# preferred unit of receiving I/O, e.g. MD stripe width.

	# minimum_io_size is used if optimal_io_size is undefined (0).

	# If md_chunk_alignment is enabled, that detects the optimal_io_size.

	# default_data_alignment and md_chunk_alignment will be overridden

	# if they are not aligned with the value detected for this setting.

	# This setting is overridden by data_alignment and the --dataalignment

	# option.

	data_alignment_detection = 1

	# Configuration option devices/data_alignment.

	# Align the start of a PV data area with this number of KiB.

	# When non-zero, this setting overrides default_data_alignment.

	# Set to 0 to disable, in which case default_data_alignment

	# is used to align the first PE in units of MiB.

	# This setting is overridden by the --dataalignment option.

	data_alignment = 0

	# Configuration option devices/data_alignment_offset_detection.

	# Shift the start of an aligned PV data area based on sysfs information.

	# After a PV data area is aligned, it will be shifted by the

	# alignment_offset exposed in sysfs. This offset is often 0, but may

	# be non-zero. Certain 4KiB sector drives that compensate for windows

	# partitioning will have an alignment_offset of 3584 bytes (sector 7

	# is the lowest aligned logical block, the 4KiB sectors start at

	# LBA -1, and consequently sector 63 is aligned on a 4KiB boundary).

	# This setting is overridden by the --dataalignmentoffset option.

	data_alignment_offset_detection = 1

	# Configuration option devices/ignore_suspended_devices.

	# Ignore DM devices that have I/O suspended while scanning devices.

	# Otherwise, LVM waits for a suspended device to become accessible.

	# This should only be needed in recovery situations.

	ignore_suspended_devices = 0

	# Configuration option devices/ignore_lvm_mirrors.

	# Do not scan 'mirror' LVs to avoid possible deadlocks.

	# This avoids possible deadlocks when using the 'mirror' segment type.

	# This setting determines whether LVs using the 'mirror' segment type

	# are scanned for LVM labels. This affects the ability of mirrors to

	# be used as physical volumes. If this setting is enabled, it is

	# impossible to create VGs on top of mirror LVs, i.e. to stack VGs on

	# mirror LVs. If this setting is disabled, allowing mirror LVs to be

	# scanned, it may cause LVM processes and I/O to the mirror to become

	# blocked. This is due to the way that the mirror segment type handles

	# failures. In order for the hang to occur, an LVM command must be run

	# just after a failure and before the automatic LVM repair process

	# takes place, or there must be failures in multiple mirrors in the

	# same VG at the same time with write failures occurring moments before

	# a scan of the mirror's labels. The 'mirror' scanning problems do not

	# apply to LVM RAID types like 'raid1' which handle failures in a

	# different way, making them a better choice for VG stacking.

	ignore_lvm_mirrors = 1

	# Configuration option devices/require_restorefile_with_uuid.

	# Allow use of pvcreate --uuid without requiring --restorefile.

	require_restorefile_with_uuid = 1

	# Configuration option devices/pv_min_size.

	# Minimum size in KiB of block devices which can be used as PVs.

	# In a clustered environment all nodes must use the same value.

	# Any value smaller than 512KiB is ignored. The previous built-in

	# value was 512.

	pv_min_size = 2048

	# Configuration option devices/issue_discards.

	# Issue discards to PVs that are no longer used by an LV.

	# Discards are sent to an LV's underlying physical volumes when the LV

	# is no longer using the physical volumes' space, e.g. lvremove,

	# lvreduce. Discards inform the storage that a region is no longer

	# used. Storage that supports discards advertise the protocol-specific

	# way discards should be issued by the kernel (TRIM, UNMAP, or

	# WRITE SAME with UNMAP bit set). Not all storage will support or

	# benefit from discards, but SSDs and thinly provisioned LUNs

	# generally do. If enabled, discards will only be issued if both the

	# storage and kernel provide support.

	issue_discards = 0

	# Configuration option devices/allow_changes_with_duplicate_pvs.

	# Allow VG modification while a PV appears on multiple devices.

	# When a PV appears on multiple devices, LVM attempts to choose the

	# best device to use for the PV. If the devices represent the same

	# underlying storage, the choice has minimal consequence. If the

	# devices represent different underlying storage, the wrong choice

	# can result in data loss if the VG is modified. Disabling this

	# setting is the safest option because it prevents modifying a VG

	# or activating LVs in it while a PV appears on multiple devices.

	# Enabling this setting allows the VG to be used as usual even with

	# uncertain devices.

	allow_changes_with_duplicate_pvs = 0

	# Configuration option devices/allow_mixed_block_sizes.

	# Allow PVs in the same VG with different logical block sizes.

	# When allowed, the user is responsible to ensure that an LV is

	# using PVs with matching block sizes when necessary.

	allow_mixed_block_sizes = 0

}

# Configuration section allocation.

# How LVM selects space and applies properties to LVs.

allocation {

	# Configuration option allocation/cling_tag_list.

	# Advise LVM which PVs to use when searching for new space.

	# When searching for free space to extend an LV, the 'cling' allocation

	# policy will choose space on the same PVs as the last segment of the

	# existing LV. If there is insufficient space and a list of tags is

	# defined here, it will check whether any of them are attached to the

	# PVs concerned and then seek to match those PV tags between existing

	# extents and new extents.

	#

	# Example

	# Use the special tag "@*" as a wildcard to match any PV tag:

	# cling_tag_list = [ "@*" ]

	# LVs are mirrored between two sites within a single VG, and

	# PVs are tagged with either @site1 or @site2 to indicate where

	# they are situated:

	# cling_tag_list = [ "@site1", "@site2" ]

	#

	# This configuration option does not have a default value defined.

	# Configuration option allocation/maximise_cling.

	# Use a previous allocation algorithm.

	# Changes made in version 2.02.85 extended the reach of the 'cling'

	# policies to detect more situations where data can be grouped onto

	# the same disks. This setting can be used to disable the changes

	# and revert to the previous algorithm.

	maximise_cling = 1

	# Configuration option allocation/use_blkid_wiping.

	# Use blkid to detect and erase existing signatures on new PVs and LVs.

	# The blkid library can detect more signatures than the native LVM

	# detection code, but may take longer. LVM needs to be compiled with

	# blkid wiping support for this setting to apply. LVM native detection

	# code is currently able to recognize: MD device signatures,

	# swap signature, and LUKS signatures. To see the list of signatures

	# recognized by blkid, check the output of the 'blkid -k' command.

	use_blkid_wiping = 1

	# Configuration option allocation/wipe_signatures_when_zeroing_new_lvs.

	# Look for and erase any signatures while zeroing a new LV.

	# The --wipesignatures option overrides this setting.

	# Zeroing is controlled by the -Z/--zero option, and if not specified,

	# zeroing is used by default if possible. Zeroing simply overwrites the

	# first 4KiB of a new LV with zeroes and does no signature detection or

	# wiping. Signature wiping goes beyond zeroing and detects exact types

	# and positions of signatures within the whole LV. It provides a

	# cleaner LV after creation as all known signatures are wiped. The LV

	# is not claimed incorrectly by other tools because of old signatures

	# from previous use. The number of signatures that LVM can detect

	# depends on the detection code that is selected (see

	# use_blkid_wiping.) Wiping each detected signature must be confirmed.

	# When this setting is disabled, signatures on new LVs are not detected

	# or erased unless the --wipesignatures option is used directly.

	wipe_signatures_when_zeroing_new_lvs = 1

	# Configuration option allocation/mirror_logs_require_separate_pvs.

	# Mirror logs and images will always use different PVs.

	# The default setting changed in version 2.02.85.

	mirror_logs_require_separate_pvs = 0

	# Configuration option allocation/raid_stripe_all_devices.

	# Stripe across all PVs when RAID stripes are not specified.

	# If enabled, all PVs in the VG or on the command line are used for

	# raid0/4/5/6/10 when the command does not specify the number of

	# stripes to use.

	# This was the default behaviour until release 2.02.162.

	# This configuration option has an automatic default value.

	# raid_stripe_all_devices = 0

	# Configuration option allocation/cache_pool_metadata_require_separate_pvs.

	# Cache pool metadata and data will always use different PVs.

	# This configuration option has an automatic default value.

	# cache_pool_metadata_require_separate_pvs = 0

	# Configuration option allocation/cache_metadata_format.

	# Sets default metadata format for new cache.

	#

	# Accepted values:

	#   0  Automatically detected best available format

	#   1  Original format

	#   2  Improved 2nd. generation format

	#

	# This configuration option has an automatic default value.

	# cache_metadata_format = 0

	# Configuration option allocation/cache_mode.

	# The default cache mode used for new cache.

	#

	# Accepted values:

	#   writethrough

	#     Data blocks are immediately written from the cache to disk.

	#   writeback

	#     Data blocks are written from the cache back to disk after some

	#     delay to improve performance.

	#

	# This setting replaces allocation/cache_pool_cachemode.

	# This configuration option has an automatic default value.

	# cache_mode = "writethrough"

	# Configuration option allocation/cache_policy.

	# The default cache policy used for new cache volume.

	# Since kernel 4.2 the default policy is smq (Stochastic multiqueue),

	# otherwise the older mq (Multiqueue) policy is selected.

	# This configuration option does not have a default value defined.

	# Configuration section allocation/cache_settings.

	# Settings for the cache policy.

	# See documentation for individual cache policies for more info.

	# This configuration section has an automatic default value.

	# cache_settings {

	# }

	# Configuration option allocation/cache_pool_chunk_size.

	# The minimal chunk size in KiB for cache pool volumes.

	# Using a chunk_size that is too large can result in wasteful use of

	# the cache, where small reads and writes can cause large sections of

	# an LV to be mapped into the cache. However, choosing a chunk_size

	# that is too small can result in more overhead trying to manage the

	# numerous chunks that become mapped into the cache. The former is

	# more of a problem than the latter in most cases, so the default is

	# on the smaller end of the spectrum. Supported values range from

	# 32KiB to 1GiB in multiples of 32.

	# This configuration option does not have a default value defined.

	# Configuration option allocation/cache_pool_max_chunks.

	# The maximum number of chunks in a cache pool.

	# For cache target v1.9 the recommended maximumm is 1000000 chunks.

	# Using cache pool with more chunks may degrade cache performance.

	# This configuration option does not have a default value defined.

	# Configuration option allocation/thin_pool_metadata_require_separate_pvs.

	# Thin pool metadata and data will always use different PVs.

	# This configuration option has an automatic default value.

	# thin_pool_metadata_require_separate_pvs = 0

	# Configuration option allocation/thin_pool_crop_metadata.

	# Older version of lvm2 cropped pool's metadata size to 15.81 GiB.

	# This is slightly less then the actual maximum 15.88 GiB.

	# For compatibility with older version and use of cropped size set to 1.

	# This configuration option has an automatic default value.

	# thin_pool_crop_metadata = 0

	# Configuration option allocation/thin_pool_zero.

	# Thin pool data chunks are zeroed before they are first used.

	# Zeroing with a larger thin pool chunk size reduces performance.

	# This configuration option has an automatic default value.

	# thin_pool_zero = 1

	# Configuration option allocation/thin_pool_discards.

	# The discards behaviour of thin pool volumes.

	#

	# Accepted values:

	#   ignore

	#   nopassdown

	#   passdown

	#

	# This configuration option has an automatic default value.

	# thin_pool_discards = "passdown"

	# Configuration option allocation/thin_pool_chunk_size_policy.

	# The chunk size calculation policy for thin pool volumes.

	#

	# Accepted values:

	#   generic

	#     If thin_pool_chunk_size is defined, use it. Otherwise, calculate

	#     the chunk size based on estimation and device hints exposed in

	#     sysfs - the minimum_io_size. The chunk size is always at least

	#     64KiB.

	#   performance

	#     If thin_pool_chunk_size is defined, use it. Otherwise, calculate

	#     the chunk size for performance based on device hints exposed in

	#     sysfs - the optimal_io_size. The chunk size is always at least

	#     512KiB.

	#

	# This configuration option has an automatic default value.

	# thin_pool_chunk_size_policy = "generic"

	# Configuration option allocation/zero_metadata.

	# Zero whole metadata area before use with thin or cache pool.

	# This configuration option has an automatic default value.

	# zero_metadata = 1

	# Configuration option allocation/thin_pool_chunk_size.

	# The minimal chunk size in KiB for thin pool volumes.

	# Larger chunk sizes may improve performance for plain thin volumes,

	# however using them for snapshot volumes is less efficient, as it

	# consumes more space and takes extra time for copying. When unset,

	# lvm tries to estimate chunk size starting from 64KiB. Supported

	# values are in the range 64KiB to 1GiB.

	# This configuration option does not have a default value defined.

	# Configuration option allocation/physical_extent_size.

	# Default physical extent size in KiB to use for new VGs.

	# This configuration option has an automatic default value.

	# physical_extent_size = 4096

	# Configuration option allocation/vdo_use_compression.

	# Enables or disables compression when creating a VDO volume.

	# Compression may be disabled if necessary to maximize performance

	# or to speed processing of data that is unlikely to compress.

	# This configuration option has an automatic default value.

	# vdo_use_compression = 1

	# Configuration option allocation/vdo_use_deduplication.

	# Enables or disables deduplication when creating a VDO volume.

	# Deduplication may be disabled in instances where data is not expected

	# to have good deduplication rates but compression is still desired.

	# This configuration option has an automatic default value.

	# vdo_use_deduplication = 1

	# Configuration option allocation/vdo_use_metadata_hints.

	# Enables or disables whether VDO volume should tag its latency-critical

	# writes with the REQ_SYNC flag. Some device mapper targets such as dm-raid5

	# process writes with this flag at a higher priority.

	# Default is enabled.

	# This configuration option has an automatic default value.

	# vdo_use_metadata_hints = 1

	# Configuration option allocation/vdo_minimum_io_size.

	# The minimum IO size for VDO volume to accept, in bytes.

	# Valid values are 512 or 4096. The recommended and default value is 4096.

	# This configuration option has an automatic default value.

	# vdo_minimum_io_size = 4096

	# Configuration option allocation/vdo_block_map_cache_size_mb.

	# Specifies the amount of memory in MiB allocated for caching block map

	# pages for VDO volume. The value must be a multiple of 4096 and must be

	# at least 128MiB and less than 16TiB. The cache must be at least 16MiB

	# per logical thread. Note that there is a memory overhead of 15%.

	# This configuration option has an automatic default value.

	# vdo_block_map_cache_size_mb = 128

	# Configuration option allocation/vdo_block_map_period.

	# The speed with which the block map cache writes out modified block map pages.

	# A smaller era length is likely to reduce the amount time spent rebuilding,

	# at the cost of increased block map writes during normal operation.

	# The maximum and recommended value is 16380; the minimum value is 1.

	# This configuration option has an automatic default value.

	# vdo_block_map_period = 16380

	# Configuration option allocation/vdo_check_point_frequency.

	# The default check point frequency for VDO volume.

	# This configuration option has an automatic default value.

	# vdo_check_point_frequency = 0

	# Configuration option allocation/vdo_use_sparse_index.

	# Enables sparse indexing for VDO volume.

	# This configuration option has an automatic default value.

	# vdo_use_sparse_index = 0

	# Configuration option allocation/vdo_index_memory_size_mb.

	# Specifies the amount of index memory in MiB for VDO volume.

	# The value must be at least 256MiB and at most 1TiB.

	# This configuration option has an automatic default value.

	# vdo_index_memory_size_mb = 256

	# Configuration option allocation/vdo_slab_size_mb.

	# Specifies the size in MiB of the increment by which a VDO is grown.

	# Using a smaller size constrains the total maximum physical size

	# that can be accommodated. Must be a power of two between 128MiB and 32GiB.

	# This configuration option has an automatic default value.

	# vdo_slab_size_mb = 2048

	# Configuration option allocation/vdo_ack_threads.

	# Specifies the number of threads to use for acknowledging

	# completion of requested VDO I/O operations.

	# The value must be at in range [0..100].

	# This configuration option has an automatic default value.

	# vdo_ack_threads = 1

	# Configuration option allocation/vdo_bio_threads.

	# Specifies the number of threads to use for submitting I/O

	# operations to the storage device of VDO volume.

	# The value must be in range [1..100]

	# Each additional thread after the first will use an additional 18MiB of RAM,

	# plus 1.12 MiB of RAM per megabyte of configured read cache size.

	# This configuration option has an automatic default value.

	# vdo_bio_threads = 4

	# Configuration option allocation/vdo_bio_rotation.

	# Specifies the number of I/O operations to enqueue for each bio-submission

	# thread before directing work to the next. The value must be in range [1..1024].

	# This configuration option has an automatic default value.

	# vdo_bio_rotation = 64

	# Configuration option allocation/vdo_cpu_threads.

	# Specifies the number of threads to use for CPU-intensive work such as

	# hashing or compression for VDO volume. The value must be in range [1..100]

	# This configuration option has an automatic default value.

	# vdo_cpu_threads = 2

	# Configuration option allocation/vdo_hash_zone_threads.

	# Specifies the number of threads across which to subdivide parts of the VDO

	# processing based on the hash value computed from the block data.

	# The value must be at in range [0..100].

	# vdo_hash_zone_threads, vdo_logical_threads and vdo_physical_threads must be

	# either all zero or all non-zero.

	# This configuration option has an automatic default value.

	# vdo_hash_zone_threads = 1

	# Configuration option allocation/vdo_logical_threads.

	# Specifies the number of threads across which to subdivide parts of the VDO

	# processing based on the hash value computed from the block data.

	# A logical thread count of 9 or more will require explicitly specifying

	# a sufficiently large block map cache size, as well.

	# The value must be in range [0..100].

	# vdo_hash_zone_threads, vdo_logical_threads and vdo_physical_threads must be

	# either all zero or all non-zero.

	# This configuration option has an automatic default value.

	# vdo_logical_threads = 1

	# Configuration option allocation/vdo_physical_threads.

	# Specifies the number of threads across which to subdivide parts of the VDO

	# processing based on physical block addresses.

	# Each additional thread after the first will use an additional 10MiB of RAM.

	# The value must be in range [0..16].

	# vdo_hash_zone_threads, vdo_logical_threads and vdo_physical_threads must be

	# either all zero or all non-zero.

	# This configuration option has an automatic default value.

	# vdo_physical_threads = 1

	# Configuration option allocation/vdo_write_policy.

	# Specifies the write policy:

	# auto  - VDO will check the storage device and determine whether it supports flushes.

	#         If it does, VDO will run in async mode, otherwise it will run in sync mode.

	# sync  - Writes are acknowledged only after data is stably written.

	#         This policy is not supported if the underlying storage is not also synchronous.

	# async - Writes are acknowledged after data has been cached for writing to stable storage.

	#         Data which has not been flushed is not guaranteed to persist in this mode.

	# This configuration option has an automatic default value.

	# vdo_write_policy = "auto"

	# Configuration option allocation/vdo_max_discard.

	# Specified te maximum size of discard bio accepted, in 4096 byte blocks.

	# I/O requests to a VDO volume are normally split into 4096-byte blocks,

	# and processed up to 2048 at a time. However, discard requests to a VDO volume

	# can be automatically split to a larger size, up to <max discard> 4096-byte blocks

	# in a single bio, and are limited to 1500 at a time.

	# Increasing this value may provide better overall performance, at the cost of

	# increased latency for the individual discard requests.

	# The default and minimum is 1. The maximum is UINT_MAX / 4096.

	# This configuration option has an automatic default value.

	# vdo_max_discard = 1

	# Configuration option allocation/vdo_pool_header_size.

	# Specified the emptry header size in KiB at the front and end of vdo pool device.

	# This configuration option has an automatic default value.

	# vdo_pool_header_size = 512

}

# Configuration section log.

# How LVM log information is reported.

log {

	# Configuration option log/report_command_log.

	# Enable or disable LVM log reporting.

	# If enabled, LVM will collect a log of operations, messages,

	# per-object return codes with object identification and associated

	# error numbers (errnos) during LVM command processing. Then the

	# log is either reported solely or in addition to any existing

	# reports, depending on LVM command used. If it is a reporting command

	# (e.g. pvs, vgs, lvs, lvm fullreport), then the log is reported in

	# addition to any existing reports. Otherwise, there's only log report

	# on output. For all applicable LVM commands, you can request that

	# the output has only log report by using --logonly command line

	# option. Use log/command_log_cols and log/command_log_sort settings

	# to define fields to display and sort fields for the log report.

	# You can also use log/command_log_selection to define selection

	# criteria used each time the log is reported.

	# This configuration option has an automatic default value.

	# report_command_log = 0

	# Configuration option log/command_log_sort.

	# List of columns to sort by when reporting command log.

	# See <lvm command> --logonly --configreport log -o help

	# for the list of possible fields.

	# This configuration option has an automatic default value.

	# command_log_sort = "log_seq_num"

	# Configuration option log/command_log_cols.

	# List of columns to report when reporting command log.

	# See <lvm command> --logonly --configreport log -o help

	# for the list of possible fields.

	# This configuration option has an automatic default value.

	# command_log_cols = "log_seq_num,log_type,log_context,log_object_type,log_object_name,log_object_id,log_object_group,log_object_group_id,log_message,log_errno,log_ret_code"

	# Configuration option log/command_log_selection.

	# Selection criteria used when reporting command log.

	# You can define selection criteria that are applied each

	# time log is reported. This way, it is possible to control the

	# amount of log that is displayed on output and you can select

	# only parts of the log that are important for you. To define

	# selection criteria, use fields from log report. See also

	# <lvm command> --logonly --configreport log -S help for the

	# list of possible fields and selection operators. You can also

	# define selection criteria for log report on command line directly

	# using <lvm command> --configreport log -S <selection criteria>

	# which has precedence over log/command_log_selection setting.

	# For more information about selection criteria in general, see

	# lvm(8) man page.

	# This configuration option has an automatic default value.

	# command_log_selection = "!(log_type=status && message=success)"

	# Configuration option log/verbose.

	# Controls the messages sent to stdout or stderr.

	verbose = 0

	# Configuration option log/silent.

	# Suppress all non-essential messages from stdout.

	# This has the same effect as -qq. When enabled, the following commands

	# still produce output: dumpconfig, lvdisplay, lvmdiskscan, lvs, pvck,

	# pvdisplay, pvs, version, vgcfgrestore -l, vgdisplay, vgs.

	# Non-essential messages are shifted from log level 4 to log level 5

	# for syslog and lvm2_log_fn purposes.

	# Any 'yes' or 'no' questions not overridden by other arguments are

	# suppressed and default to 'no'.

	silent = 0

	# Configuration option log/syslog.

	# Send log messages through syslog.

	syslog = 1

	# Configuration option log/file.

	# Write error and debug log messages to a file specified here.

	# This configuration option does not have a default value defined.

	# Configuration option log/overwrite.

	# Overwrite the log file each time the program is run.

	overwrite = 0

	# Configuration option log/level.

	# The level of log messages that are sent to the log file or syslog.

	# There are 6 syslog-like log levels currently in use: 2 to 7 inclusive.

	# 7 is the most verbose (LOG_DEBUG).

	level = 0

	# Configuration option log/indent.

	# Indent messages according to their severity.

	# This configuration option has an automatic default value.

	# indent = 0

	# Configuration option log/command_names.

	# Display the command name on each line of output.

	command_names = 0

	# Configuration option log/prefix.

	# A prefix to use before the log message text.

	# (After the command name, if selected).

	# Two spaces allows you to see/grep the severity of each message.

	# To make the messages look similar to the original LVM tools use:

	# indent = 0, command_names = 1, prefix = " -- "

	prefix = "  "

	# Configuration option log/activation.

	# Log messages during activation.

	# Don't use this in low memory situations (can deadlock).

	activation = 0

	# Configuration option log/debug_classes.

	# Select log messages by class.

	# Some debugging messages are assigned to a class and only appear in

	# debug output if the class is listed here. Classes currently

	# available: memory, devices, io, activation, allocation,

	# metadata, cache, locking, lvmpolld. Use "all" to see everything.

	debug_classes = [ "memory", "devices", "io", "activation", "allocation", "metadata", "cache", "locking", "lvmpolld", "dbus" ]

	# Configuration option log/debug_file_fields.

	# The fields included in debug output written to log file.

	# Use "all" to include everything (the default).

	# This configuration option is advanced.

	# This configuration option has an automatic default value.

	# debug_file_fields = [ "time", "command", "fileline", "message" ]

	# Configuration option log/debug_output_fields.

	# The fields included in debug output written to stderr.

	# Use "all" to include everything (the default).

	# This configuration option is advanced.

	# This configuration option has an automatic default value.

	# debug_output_fields = [ "time", "command", "fileline", "message" ]

}

# Configuration section backup.

# How LVM metadata is backed up and archived.

# In LVM, a 'backup' is a copy of the metadata for the current system,

# and an 'archive' contains old metadata configurations. They are

# stored in a human readable text format.

backup {

	# Configuration option backup/backup.

	# Maintain a backup of the current metadata configuration.

	# Think very hard before turning this off!

	backup = 1

	# Configuration option backup/backup_dir.

	# Location of the metadata backup files.

	# Remember to back up this directory regularly!

	backup_dir = "/etc/lvm/backup"

	# Configuration option backup/archive.

	# Maintain an archive of old metadata configurations.

	# Think very hard before turning this off.

	archive = 1

	# Configuration option backup/archive_dir.

	# Location of the metdata archive files.

	# Remember to back up this directory regularly!

	archive_dir = "/etc/lvm/archive"

	# Configuration option backup/retain_min.

	# Minimum number of archives to keep.

	retain_min = 10

	# Configuration option backup/retain_days.

	# Minimum number of days to keep archive files.

	retain_days = 30

}

# Configuration section shell.

# Settings for running LVM in shell (readline) mode.

shell {

	# Configuration option shell/history_size.

	# Number of lines of history to store in ~/.lvm_history.

	history_size = 100

}

# Configuration section global.

# Miscellaneous global LVM settings.

global {

	# Configuration option global/umask.

	# The file creation mask for any files and directories created.

	# Interpreted as octal if the first digit is zero.

	umask = 077

	# Configuration option global/test.

	# No on-disk metadata changes will be made in test mode.

	# Equivalent to having the -t option on every command.

	test = 0

	# Configuration option global/units.

	# Default value for --units argument.

	units = "r"

	# Configuration option global/si_unit_consistency.

	# Distinguish between powers of 1024 and 1000 bytes.

	# The LVM commands distinguish between powers of 1024 bytes,

	# e.g. KiB, MiB, GiB, and powers of 1000 bytes, e.g. KB, MB, GB.

	# If scripts depend on the old behaviour, disable this setting

	# temporarily until they are updated.

	si_unit_consistency = 1

	# Configuration option global/suffix.

	# Display unit suffix for sizes.

	# This setting has no effect if the units are in human-readable form

	# (global/units = "h") in which case the suffix is always displayed.

	suffix = 1

	# Configuration option global/activation.

	# Enable/disable communication with the kernel device-mapper.

	# Disable to use the tools to manipulate LVM metadata without

	# activating any logical volumes. If the device-mapper driver

	# is not present in the kernel, disabling this should suppress

	# the error messages.

	activation = 1

	# Configuration option global/proc.

	# Location of proc filesystem.

	# This configuration option is advanced.

	proc = "/proc"

	# Configuration option global/etc.

	# Location of /etc system configuration directory.

	etc = "/etc"

	# Configuration option global/wait_for_locks.

	# When disabled, fail if a lock request would block.

	wait_for_locks = 1

	# Configuration option global/locking_dir.

	# Directory to use for LVM command file locks.

	# Local non-LV directory that holds file-based locks while commands are

	# in progress. A directory like /tmp that may get wiped on reboot is OK.

	locking_dir = "/run/lock/lvm"

	# Configuration option global/prioritise_write_locks.

	# Allow quicker VG write access during high volume read access.

	# When there are competing read-only and read-write access requests for

	# a volume group's metadata, instead of always granting the read-only

	# requests immediately, delay them to allow the read-write requests to

	# be serviced. Without this setting, write access may be stalled by a

	# high volume of read-only requests. This option only affects file locks.

	prioritise_write_locks = 1

	# Configuration option global/library_dir.

	# Search this directory first for shared libraries.

	# This configuration option does not have a default value defined.

	# Configuration option global/abort_on_internal_errors.

	# Abort a command that encounters an internal error.

	# Treat any internal errors as fatal errors, aborting the process that