SSD partition alignment considerations

Cam Hutchison's picture

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I'm about to do a fresh install of Debian onto a new box with a Crucial
M4 128GB SSD. I want to ensure that I get the best performance I can out
of the SSD so I want to make sure I take care of any partition alignment
issues.

I have read tytso's blog post
(http://ldn.linuxfoundation.org/blog-entry/aligning-filesystems-ssd%E2%80%99s-erase-block-size)
but that post is a couple of years old now and may not be relevant.
Also, I cannot find any specific information on the M4's erase block
size but some hints suggest it may be 512kiB, not the 128kiB used in
that blog post (and the c/h/s settings no longer work for 512kiB
alignment).

It is necessary to worry about alignment anymore with modern SSDs? The
Debian installer did not seem to have any special handling that I could
see, so I suspect I would have to pre-partition the drive and tell the
installer to use the existing partitions.

SSD partition alignment considerations

Stan Hoeppner's picture

On 5/30/2011 10:39 PM, Cam Hutchison wrote:
> I'm about to do a fresh install of Debian onto a new box with a Crucial
> M4 128GB SSD. I want to ensure that I get the best performance I can out
> of the SSD so I want to make sure I take care of any partition alignment
> issues.
>
> I have read tytso's blog post
> (http://ldn.linuxfoundation.org/blog-entry/aligning-filesystems-ssd%E2%80%99s-erase-block-size)
> but that post is a couple of years old now and may not be relevant.
> Also, I cannot find any specific information on the M4's erase block
> size but some hints suggest it may be 512kiB, not the 128kiB used in
> that blog post (and the c/h/s settings no longer work for 512kiB
> alignment).
>
> It is necessary to worry about alignment anymore with modern SSDs? The
> Debian installer did not seem to have any special handling that I could
> see, so I suspect I would have to pre-partition the drive and tell the
> installer to use the existing partitions.

General consensus is to start your first partition at 1,048,576 bytes,
as it is evenly divisible by 512, 4096, 131,072, and 524,288 bytes,
covering all sector, filesystem block, and erase block size possibilities.

SSD partition alignment considerations

Tony van der Hoff's picture

On 31/05/11 10:20, Stan Hoeppner wrote:
>
> General consensus is to start your first partition at 1,048,576 bytes,
> as it is evenly divisible by 512, 4096, 131,072, and 524,288 bytes,
> covering all sector, filesystem block, and erase block size possibilities.
>
General consensus by whom, Stan? Have you any references?