HP 3PAR RedHat and Oracle Linux Implementation Guide

Device Boot Start End Blocks Id System
/dev/sdh1 32768 10485759 5226496 83 Linux
If the -c or -u flag is not used during the creation of the partition, then the start sector is 30876,
and a warning "Partition 1 does not start on physical sector boundary" appears after the partition
is created.
Example without the -c flag or -u flag:
# fdisk /dev/sdh
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1018, default 4):
Using default value 4
Last cylinder, +cylinders or +size{K,M,G} (4-1018, default 1018):
Using default value 1018
# fdisk -l -u /dev/sdh
Disk /dev/sdh: 5368 MB, 5368709120 bytes
166 heads, 62 sectors/track, 1018 cylinders, total 10485760 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 16384 bytes / 16777216 bytes
Disk identifier: 0x2d8b4dbe
Device Boot Start End Blocks Id System
/dev/sdh1 30876 10477255 5223190 83 Linux
Partition 1 does not start on physical sector boundary.
Also, if the alignment is not proper, the following warning about poor performance during the
creation of ext filesystems appears.
# mkfs.ext4 /dev/mapper/350002ac000020121p1
mke2fs 1.41.12 (17-May-2010)
/dev/mapper/350002ac000020121p1 alignment is offset by 2048 bytes.
This may result in very poor performance, (re)-partitioning suggested.
The same result can be achieved using the parted command, with the units in GB so that proper
alignment occurs on HP 3PAR OS 3.1.1 or later. The following example shows alignment starting
at sector 32768:
# parted /dev/sdh
GNU Parted 2.1
Using /dev/sdh
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel
New disk label type? msdos
(parted) unit gb
(parted) mkpart primary
120 Modifying HP 3PAR Devices on the Host