[lvm-devel] LVM2 ./WHATS_NEW doc/example.conf.in lib/confi ...
snitzer at sourceware.org
snitzer at sourceware.org
Fri Aug 20 20:59:09 UTC 2010
CVSROOT: /cvs/lvm2
Module name: LVM2
Changes by: snitzer at sourceware.org 2010-08-20 20:59:07
Modified files:
. : WHATS_NEW
doc : example.conf.in
lib/config : defaults.h
lib/format_text: format-text.c
lib/metadata : metadata.c
Log message:
Update heuristic used for default and detected data alignment.
Add "devices/default_data_alignment" to lvm.conf to control the internal
default that LVM2 uses: 0==64k, 1==1MB, 2==2MB, etc.
If --dataalignment (or lvm.conf's "devices/data_alignment") is specified
then it is always used to align the start of the data area. This means
the md_chunk_alignment and data_alignment_detection are disabled if set.
(Same now applies to pvcreate --dataalignmentoffset, the specified value
will be used instead of the result from data_alignment_offset_detection)
set_pe_align() still looks to use the determined default alignment
(based on lvm.conf's default_data_alignment) if the default is a
multiple of the MD or topology detected values.
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.1718&r2=1.1719
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/doc/example.conf.in.diff?cvsroot=lvm2&r1=1.8&r2=1.9
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/config/defaults.h.diff?cvsroot=lvm2&r1=1.66&r2=1.67
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/format_text/format-text.c.diff?cvsroot=lvm2&r1=1.142&r2=1.143
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/metadata/metadata.c.diff?cvsroot=lvm2&r1=1.395&r2=1.396
--- LVM2/WHATS_NEW 2010/08/20 20:35:55 1.1718
+++ LVM2/WHATS_NEW 2010/08/20 20:59:05 1.1719
@@ -1,5 +1,7 @@
Version 2.02.74 -
==================================
+ Update heuristic used for default and detected data alignment.
+ Add "devices/default_data_alignment" to lvm.conf.
Add implmentation for simple numeric 'get' property functions.
Define GET_NUM_PROPERTY_FN macro to simplify numeric property 'get' function
Add properties.[ch] to lib/report, defined based on columns.h.
--- LVM2/doc/example.conf.in 2010/08/16 22:54:36 1.8
+++ LVM2/doc/example.conf.in 2010/08/20 20:59:05 1.9
@@ -98,6 +98,11 @@
# 1 enables; 0 disables.
md_chunk_alignment = 1
+ # Default alignment of the start of a data area in MB. If set to 0,
+ # a small value of 64KB will be used, which was the default until
+ # LVM2 version 2.02.73. Set to 1 for 1MiB, 2 for 2MiB, etc.
+ default_data_alignment = 1
+
# By default, the start of a PV's data area will be a multiple of
# the 'minimum_io_size' or 'optimal_io_size' exposed in sysfs.
# - minimum_io_size - the smallest request the device can perform
@@ -111,9 +116,9 @@
data_alignment_detection = 1
# Alignment (in KB) of start of data area when creating a new PV.
- # If a PV is placed directly upon an md device and md_chunk_alignment or
- # data_alignment_detection is enabled this parameter is ignored.
- # Set to 0 for the default alignment of 1MB or page size, if larger.
+ # md_chunk_alignment and data_alignment_detection are disabled if set.
+ # Set to 0 for the default alignment (see: data_alignment_default)
+ # or page size, if larger.
data_alignment = 0
# By default, the start of the PV's aligned data area will be shifted by
@@ -122,6 +127,7 @@
# windows partitioning will have an alignment_offset of 3584 bytes
# (sector 7 is the lowest aligned logical block, the 4KB sectors start
# at LBA -1, and consequently sector 63 is aligned on a 4KB boundary).
+ # But note that pvcreate --dataalignmentoffset will skip this detection.
# 1 enables; 0 disables.
data_alignment_offset_detection = 1
--- LVM2/lib/config/defaults.h 2010/08/16 22:54:36 1.66
+++ LVM2/lib/config/defaults.h 2010/08/20 20:59:05 1.67
@@ -17,6 +17,7 @@
#define _LVM_DEFAULTS_H
#define DEFAULT_PE_ALIGN 2048
+#define DEFAULT_PE_ALIGN_OLD 128
#define DEFAULT_ARCHIVE_ENABLED 1
#define DEFAULT_BACKUP_ENABLED 1
@@ -33,6 +34,7 @@
#define DEFAULT_MD_CHUNK_ALIGNMENT 1
#define DEFAULT_IGNORE_SUSPENDED_DEVICES 1
#define DEFAULT_REQUIRE_RESTOREFILE_WITH_UUID 1
+#define DEFAULT_DATA_ALIGNMENT 1
#define DEFAULT_DATA_ALIGNMENT_OFFSET_DETECTION 1
#define DEFAULT_DATA_ALIGNMENT_DETECTION 1
--- LVM2/lib/format_text/format-text.c 2010/08/03 18:19:42 1.142
+++ LVM2/lib/format_text/format-text.c 2010/08/20 20:59:07 1.143
@@ -1861,16 +1861,20 @@
0) * 2;
if (set_pe_align(pv, data_alignment) != data_alignment &&
- data_alignment)
- log_warn("WARNING: %s: Overriding data alignment to "
- "%lu sectors (requested %lu sectors)",
- pv_dev_name(pv), pv->pe_align, data_alignment);
+ data_alignment) {
+ log_error("%s: invalid data alignment of "
+ "%lu sectors (requested %lu sectors)",
+ pv_dev_name(pv), pv->pe_align, data_alignment);
+ return 0;
+ }
if (set_pe_align_offset(pv, data_alignment_offset) != data_alignment_offset &&
- data_alignment_offset)
- log_warn("WARNING: %s: Overriding data alignment offset to "
- "%lu sectors (requested %lu sectors)",
- pv_dev_name(pv), pv->pe_align_offset, data_alignment_offset);
+ data_alignment_offset) {
+ log_error("%s: invalid data alignment offset of "
+ "%lu sectors (requested %lu sectors)",
+ pv_dev_name(pv), pv->pe_align_offset, data_alignment_offset);
+ return 0;
+ }
if (pv->pe_align < pv->pe_align_offset) {
log_error("%s: pe_align (%lu sectors) must not be less "
--- LVM2/lib/metadata/metadata.c 2010/08/20 12:43:49 1.395
+++ LVM2/lib/metadata/metadata.c 2010/08/20 20:59:07 1.396
@@ -62,23 +62,38 @@
const char _really_init[] =
"Really INITIALIZE physical volume \"%s\" of volume group \"%s\" [y/n]? ";
-static int _alignment_overrides_default(unsigned long data_alignment)
+static int _alignment_overrides_default(unsigned long data_alignment,
+ unsigned long default_pe_align)
{
- return data_alignment && (DEFAULT_PE_ALIGN % data_alignment);
+ return data_alignment && (default_pe_align % data_alignment);
}
unsigned long set_pe_align(struct physical_volume *pv, unsigned long data_alignment)
{
- unsigned long temp_pe_align;
+ unsigned long default_pe_align, temp_pe_align;
if (pv->pe_align)
goto out;
- if (data_alignment)
+ if (data_alignment) {
+ /* Always use specified data_alignment */
pv->pe_align = data_alignment;
+ goto out;
+ }
+
+ default_pe_align = find_config_tree_int(pv->fmt->cmd,
+ "devices/default_data_alignment",
+ DEFAULT_DATA_ALIGNMENT);
+
+ if (default_pe_align)
+ /* align on 1 MiB multiple */
+ default_pe_align *= DEFAULT_PE_ALIGN;
else
- pv->pe_align = MAX((DEFAULT_PE_ALIGN << SECTOR_SHIFT),
- lvm_getpagesize()) >> SECTOR_SHIFT;
+ /* align on 64 KiB multiple (old default) */
+ default_pe_align = DEFAULT_PE_ALIGN_OLD;
+
+ pv->pe_align = MAX((default_pe_align << SECTOR_SHIFT),
+ lvm_getpagesize()) >> SECTOR_SHIFT;
if (!pv->dev)
goto out;
@@ -89,8 +104,8 @@
if (find_config_tree_bool(pv->fmt->cmd, "devices/md_chunk_alignment",
DEFAULT_MD_CHUNK_ALIGNMENT)) {
temp_pe_align = dev_md_stripe_width(pv->fmt->cmd->sysfs_dir, pv->dev);
- if (_alignment_overrides_default(temp_pe_align))
- pv->pe_align = temp_pe_align;
+ if (_alignment_overrides_default(temp_pe_align, default_pe_align))
+ pv->pe_align = MAX(pv->pe_align, temp_pe_align);
}
/*
@@ -104,18 +119,18 @@
"devices/data_alignment_detection",
DEFAULT_DATA_ALIGNMENT_DETECTION)) {
temp_pe_align = dev_minimum_io_size(pv->fmt->cmd->sysfs_dir, pv->dev);
- if (_alignment_overrides_default(temp_pe_align))
- pv->pe_align = temp_pe_align;
+ if (_alignment_overrides_default(temp_pe_align, default_pe_align))
+ pv->pe_align = MAX(pv->pe_align, temp_pe_align);
temp_pe_align = dev_optimal_io_size(pv->fmt->cmd->sysfs_dir, pv->dev);
- if (_alignment_overrides_default(temp_pe_align))
- pv->pe_align = temp_pe_align;
+ if (_alignment_overrides_default(temp_pe_align, default_pe_align))
+ pv->pe_align = MAX(pv->pe_align, temp_pe_align);
}
+out:
log_very_verbose("%s: Setting PE alignment to %lu sectors.",
dev_name(pv->dev), pv->pe_align);
-out:
return pv->pe_align;
}
@@ -125,8 +140,11 @@
if (pv->pe_align_offset)
goto out;
- if (data_alignment_offset)
+ if (data_alignment_offset) {
+ /* Always use specified data_alignment_offset */
pv->pe_align_offset = data_alignment_offset;
+ goto out;
+ }
if (!pv->dev)
goto out;
@@ -142,10 +160,10 @@
pv->pe_align_offset = MAX(pv->pe_align_offset, align_offset);
}
+out:
log_very_verbose("%s: Setting PE alignment offset to %lu sectors.",
dev_name(pv->dev), pv->pe_align_offset);
-out:
return pv->pe_align_offset;
}
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