Re: [gentoo-user] MBR partition

[Joseph <syscon780@gmail.com>]

On 09/06/14 07:15, Kerin Millar wrote:
>On 06/09/2014 04:10, Joseph wrote:
>> On 09/05/14 21:02, Joseph wrote:
>>> I'm configuring MBR partition for older disk and need to know what
>>> code to enter for boot partition.
>>> My BIOS is not EFI type.
>
>Not that it particularly matters but a partition dedicated to /boot
>contains a Linux filesystem and, thus, 83 is appropriate.
>
>>
>> My current configuration:
>> fdisk -l /dev/sda
>>
>> Disk /dev/sda: 447.1 GiB, 480103981056 bytes, 937703088 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
>> Disklabel type: dos
>> Disk identifier: 0x021589e5
>>
>> Device    Boot     Start       End    Blocks  Id System
>> /dev/sda1 *         2048    155647     76800  83 Linux
>> /dev/sda2         155648   4349951   2097152  82 Linux swap / Solaris
>> /dev/sda3        4349952 937703087 466676568  83 Linux
>>
>> Does the sda1 has to start with "1" or 2048?
>
>As of util-linux-2.18, partitions are aligned to 1 MiB boundaries by
>default, so as to avoid performance degradation on SSDs and advanced
>format drives [1].
>
>Further, beginning at 2048 as opposed to 63 (in the manner of MS-DOS)
>provides more room for boot loaders such as grub to embed themselves.
>
>To have the first sector be a partition boundary is impossible because
>that is the location of the MBR and the partition table.
>
>In summary, let it be.
>
>--Kerin

Thank you for the information.
I'll continue on Monday and let you know.  If it will not boot with sector starting at 2048, I will re-partition /boot sda1 to start at 63.

-- 
Joseph