From 6f59b4476d3734c1b25ba2844d6f0cc97b0b2a98 Mon Sep 17 00:00:00 2001 From: Zdenek Kabelac Date: Thu, 29 Nov 2018 23:08:05 +0100 Subject: make: generate config update --- conf/example.conf.in | 56 +++++++++++++++++++++++++++----------------- 1 file changed, 35 insertions(+), 21 deletions(-) diff --git a/conf/example.conf.in b/conf/example.conf.in index 6b8e0d4bd9..0204f4b5a3 100644 --- a/conf/example.conf.in +++ b/conf/example.conf.in @@ -185,19 +185,24 @@ devices { fw_raid_component_detection = 0 # Configuration option devices/md_chunk_alignment. - # Align PV data blocks with md device's stripe-width. + # 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 overriden if it is not aligned + # with the value detected for this setting. + # This setting is overriden by data_alignment_detection, + # data_alignment, and the --dataalignment option. md_chunk_alignment = 1 # Configuration option devices/default_data_alignment. - # Default alignment of the start of a PV data area in MB. - # If set to 0, a value of 64KiB will be used. - # Set to 1 for 1MiB, 2 for 2MiB, etc. + # 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 overriden 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. - # Detect PV data alignment based on sysfs device information. + # 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 @@ -205,27 +210,29 @@ devices { # 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. - # This setting takes precedence over md_chunk_alignment. + # default_data_alignment and md_chunk_alignment will be overriden + # if they are not aligned with the value detected for this setting. + # This setting is overriden by data_alignment and the --dataalignment + # option. data_alignment_detection = 1 # Configuration option devices/data_alignment. - # Alignment of the start of a PV data area in KiB. - # If a PV is placed directly on an md device and md_chunk_alignment or - # data_alignment_detection are enabled, then this setting is ignored. - # Otherwise, md_chunk_alignment and data_alignment_detection are - # disabled if this is set. Set to 0 to use the default alignment or the - # page size, if larger. + # 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 overriden by the --dataalignment option. data_alignment = 0 # Configuration option devices/data_alignment_offset_detection. - # Detect PV data alignment offset based on sysfs device information. - # The start of a PV aligned data area will be shifted by the + # 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). - # pvcreate --dataalignmentoffset will skip this detection. + # This setting is overriden by the --dataalignmentoffset option. data_alignment_offset_detection = 1 # Configuration option devices/ignore_suspended_devices. @@ -1640,13 +1647,20 @@ activation { # vgmetadatacopies = 0 # Configuration option metadata/pvmetadatasize. - # Approximate number of sectors to use for each metadata copy. - # VGs with large numbers of PVs or LVs, or VGs containing complex LV - # structures, may need additional space for VG metadata. The metadata - # areas are treated as circular buffers, so unused space becomes filled - # with an archive of the most recent previous versions of the metadata. + # The default size of the metadata area in units of 512 byte sectors. + # The metadata area begins at an offset of the page size from the start + # of the device. The first PE is by default at 1 MiB from the start of + # the device. The space between these is the default metadata area size. + # The actual size of the metadata area may be larger than what is set + # here due to default_data_alignment making the first PE a MiB multiple. + # The metadata area begins with a 512 byte header and is followed by a + # circular buffer used for VG metadata text. The maximum size of the VG + # metadata is about half the size of the metadata buffer. VGs with large + # numbers of PVs or LVs, or VGs containing complex LV structures, may need + # additional space for VG metadata. The --metadatasize option overrides + # this setting. + # This configuration option does not have a default value defined. # This configuration option has an automatic default value. - # pvmetadatasize = 255 # Configuration option metadata/pvmetadataignore. # Ignore metadata areas on a new PV.