Partition 1 does not end on cylinder boundary warning in fdisk

Thanks to Werner Fischer

Older versions of the program of the package fdisk util-linux show in DOS compatibility mode, a warning at the partitions with a proper partition alignment have been established for about SSDs.

The warning Partition 1 does not end on cylinder boundary is only for DOS environments relevant, but they are virtually impossible to meet. The warning can be ignored. The call to fdisk with the-c suppresses the warning (it is the DOS compatibility mode disabled). (Note: for gnu-fdisk there is not the option-c.)

For partitions with a proper partition alignment fdisk -lu shows a warning from fdisk lcu is no warning.

Contents

Warning of fdisk -l

 user @ ubuntu-10-10: ~ $ sudo fdisk -l /dev/sda

 Disk / dev / sda: 160.0 GB, 160041885696 bytes
 255 heads, 63 sectors / track, 19457 cylinders
 Units = cylinders of 16065 * 512 = 8225280 bytes
 Sector size (logical / physical): 512 bytes / 512 bytes
 I / O size (minimum / optimal): 512 bytes / 512 bytes
 Disk identifier: 0x9349dd6c

    Device Boot Start End Blocks Id System
 / Dev/sda1 * 1 153 1227776 7 HPFS / NTFS
 Partition 1 does not end on cylinder boundary.
 / Dev/sda2 153 3801 2929 6875 7 HPFS / NTFS
 Partition 2 does not end on cylinder boundary.
 / Dev/sda3 3801 5017 9764864 83 Linux
 Partition 3 does not end on cylinder boundary.
 / Dev/sda4 5017 19458 115998720 83 Linux
 Partition 4 does not end on cylinder boundary.

Warning for fdisk -l -u

 user @ ubuntu-10-10: ~ $ sudo fdisk -l -u /dev/sda

 Disk /dev/sda: 160.0 GB, 160041885696 bytes
 255 heads, 63 sectors / track, 19457 cylinders, total 312581808 sectors
 Units = sectors of 1 * 512 = 512 bytes
 Sector size (logical / physical): 512 bytes / 512 bytes
 I / O size (minimum / optimal): 512 bytes / 512 bytes
 Disk identifier: 0x9349dd6c

    Device Boot Start End Blocks Id System
 / Dev/sda1 * 2048 2457599 1227776 7 HPFS / NTFS
 Partition 1 does not end on cylinder boundary.
 / Dev/sda2 2457600 61051349 29296875 7 HPFS / NTFS
 Partition 2 does not end on cylinder boundary.
 / Dev/sda3 61052928 80582655 9764864 83 Linux
 Partition 3 does not end on cylinder boundary.
 / Dev/sda4 80582656 312580095 115998720 83 Linux
 Partition 4 does not end on cylinder boundary.

No warning at fdisk -l -c -u

 user @ ubuntu-10-10: ~ $ sudo fdisk -l -c -u /dev/sda Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors / track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical / physical): 512 bytes / 512 bytes I / O size (minimum / optimal): 512 bytes / 512 bytes Disk identifier: Device Boot Start End Blocks 0x9349dd6c Id System / dev/sda1 * 2048 2457599 1227776 7 HPFS / NTFS / dev/sda2 2457600 61051349 29296875 7 HPFS / NTFS / dev/sda3 61052928 80582655 9764864 83 Linux / dev/sda4 80582656 312580095 115998720 83 Linux user @ ubuntu-10-10: ~ $

Fdisk manpage

Manpage fdisk util-linux 2.17.2-9 (Debian 6.0.6)

 OPTIONS
 [...]
        -C switch off DOS-compatible mode.  (Recommended)
 [...]

Fdisk manual page from util-linux 2.20.1-1ubuntu3 (Ubuntu 12.04 LTS)

Newer versions of fdisk have the previous DOS-compatible mode turned off by default (The default is non-DOS mode.)

 OPTIONS
 [...]
        -C [= mode]
               Specify the compatiblity mode, 'dos' or 'nondos'.  The default
               is non-DOS mode.  For backward compatibility, it is possible to
               use the option without the <mode> argument - then the default
               is used.  Note that the optional <mode> argument can not be sepa-
               generated from the-c option by a space, the correct form is for
               example '-c = dos'.
 [...]
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