Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 16 Nov 2013 07:05:07 -0700 (MST)
From:      Warren Block <wblock@wonkity.com>
To:        Shane Ambler <FreeBSD@ShaneWare.Biz>
Cc:        FreeBSD Questions <freebsd-questions@freebsd.org>, aurfalien <aurfalien@gmail.com>
Subject:   Re: gpart, to -a 4k or to -b 1M
Message-ID:  <alpine.BSF.2.00.1311160659060.41758@wonkity.com>
In-Reply-To: <528704C7.9050103@ShaneWare.Biz>
References:  <A0427786-1BF3-47CB-9924-7B568BA5A950@gmail.com> <alpine.BSF.2.00.1311151712370.36506@wonkity.com> <528704C7.9050103@ShaneWare.Biz>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 16 Nov 2013, Shane Ambler wrote:

> On 16/11/2013 10:46, Warren Block wrote:
>> On Fri, 15 Nov 2013, aurfalien wrote:
>>>
>>> Curious, for best practice in ensuring 4K alignment, should one do;
>>>
>>> gpart add ... -b 1M
>>>
>>> or
>>>
>>> gpart add ... -a 4k
>>>
>>> Thank in advance,
>>
>> They do different things.  '-b 1M' starts the added partition at 1M but
>> does not force it to be a multiple of 4K in size.
>>
>> '-a 4k' forces the added partition to start at the next 4K-aligned
>> block, and forces the size to be a multiple of 4K.
>>
>> I recommend both for the first filesystem partition, and '-a 4k' for
>> later ones.
>
> I believe it was related to windows co-existence but I heard a while
> back that -a 1M is a good option to use.

It doesn't hurt anything.  By rounding both starting location and length 
to 1M multiples, it still forces 4K alignment.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.00.1311160659060.41758>