Add --dataalignmentoffset to pvcreate to shift start of aligned data area

Adds pe_align_offset to 'struct physical_volume'; is initialized with
set_pe_align_offset().  After pe_start is established pe_align_offset is
added to it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/man/pvcreate.8.in b/man/pvcreate.8.in
index 4d488058..2f214e33 100644
--- a/man/pvcreate.8.in
+++ b/man/pvcreate.8.in
@@ -14,6 +14,7 @@ pvcreate \- initialize a disk or partition for use by LVM
 .RB [ \-\-metadatacopies #copies ]
 .RB [ \-\-metadatasize size ]
 .RB [ \-\-dataalignment alignment ]
+.RB [ \-\-dataalignmentoffset alignment_offset ]
 .RB [ \-\-restorefile file ]
 .RB [ \-\-setphysicalvolumesize size ]
 .RB [ \-u | \-\-uuid uuid ]
@@ -91,13 +92,18 @@ The approximate amount of space to be set aside for each metadata area.
 (The size you specify may get rounded.)
 .TP
 .BR \-\-dataalignment " alignment"
-Align the offset of the start of the data to a multiple of this number.
+Align the start of the data to a multiple of this number.
 You should also specify an appropriate \fBPhysicalExtentSize\fP when creating
 the Volume Group with \fBvgcreate\fP.
 .sp
 To see the location of the first Physical Extent of an existing Physical Volume
 use \fBpvs -o +pe_start\fP .  It will be a multiple of the requested
-\fBdata_alignment\fP.
+\fBalignment\fP.  In addition it may be shifted by \fBalignment_offset\fP from
+\fBdata_alignment_offset_detection\fP (if enabled in \fBlvm.conf\fP) or
+\fB--dataalignmentoffset\fP.
+.TP
+.BR \-\-dataalignmentoffset " alignment_offset"
+Shift the start of the data area by this additional \fBalignment_offset\fP.
 .TP
 .BR \-\-metadatacopies " copies"
 The number of metadata areas to set aside on each PV.  Currently
@@ -128,13 +134,21 @@ in the source).  Use with care.
 .TP
 .BR \-\-setphysicalvolumesize " size"
 Overrides the automatically-detected size of the PV.  Use with care.
-.SH Example
+.SH EXAMPLES
 Initialize partition #4 on the third SCSI disk and the entire fifth
 SCSI disk for later use by LVM:
 .sp
 .B pvcreate /dev/sdc4 /dev/sde
 .sp
+If the 2nd SCSI disk is a 4KB sector drive that compensates for windows
+partitioning (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) manually account for this when initializing for use by LVM:
+.sp
+.B pvcreate --dataalignmentoffset 7s /dev/sdb
+.sp
 .SH SEE ALSO
+.BR lvm.conf (5),
 .BR lvm (8),
 .BR vgcreate (8), 
 .BR vgextend (8),