Installation guide

Appendix B. The LVM Configuration Files
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# But note that pvcreate --dataalignmentoffset will skip this detection.
# 1 enables; 0 disables.
data_alignment_offset_detection = 1
# If, while scanning the system for PVs, LVM2 encounters a device-mapper
# device that has its I/O suspended, it waits for it to become accessible.
# Set this to 1 to skip such devices. This should only be needed
# in recovery situations.
ignore_suspended_devices = 0
# During each LVM operation errors received from each device are counted.
# If the counter of a particular device exceeds the limit set here, no
# further I/O is sent to that device for the remainder of the respective
# operation. Setting the parameter to 0 disables the counters altogether.
disable_after_error_count = 0
# Allow use of pvcreate --uuid without requiring --restorefile.
require_restorefile_with_uuid = 1
# Minimum size (in KB) of block devices which can be used as PVs.
# In a clustered environment all nodes must use the same value.
# Any value smaller than 512KB is ignored.
# Ignore devices smaller than 2MB such as floppy drives.
pv_min_size = 2048
# The original built-in setting was 512 up to and including version 2.02.84.
# pv_min_size = 512
# Issue discards to a logical volumes's underlying physical volume(s) when
# the logical volume is no longer using the physical volumes' space (e.g.
# lvremove, lvreduce, etc). Discards inform the storage that a region is
# no longer in use. 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 set
# to 1, discards will only be issued if both the storage and kernel provide
# support.
# 1 enables; 0 disables.
issue_discards = 0
}
# This section allows you to configure the way in which LVM selects
# free space for its Logical Volumes.
#allocation {
# 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.
# Use the special tag "@*" as a wildcard to match any PV tag.
#
# Example: LVs are mirrored between two sites within a single VG.
# PVs are tagged with either @site1 or @site2 to indicate where
# they are situated.
#
# cling_tag_list = [ "@site1", "@site2" ]
# cling_tag_list = [ "@*" ]
#
# 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. Set this to 0 to revert to the previous
# algorithm.
#
# maximise_cling = 1
#