[CentOS] ext4, 4k sector alignment

m.roth at 5-cent.us m.roth at 5-cent.us
Mon Jul 25 17:56:38 UTC 2011

John Austin wrote:
> On Mon, 2011-07-25 at 13:23 -0400, R P Herrold wrote:
>> On Mon, 25 Jul 2011, Les Mikesell wrote:
>> > My questions for any filesystem experts are:
>> >
>> > Is there a way to adjust the existing md partitions to get the right
>> > alignment for 4k sectors without having to do a file-oriented copy to
>> > new partitions?  A resize + a dd copy to shift the position might be
>> > feasible time-wise if that would work.
>> We have some non-conformant units, and after seaching,
>> concluded that a 'wipe and rebuild' was the most time
>> efficient process for us -- YMMV
>> > Is it worth converting to ext4?
>> ext4 is pleasant in some large filesystem cases, but probably
>> overkill as a blanket option.
>> > If I start over from scratch with 6.x, will the partitioning tools
>> > automatically align for 4k sector drives (with/without lvm?)?
>> no idea if gparted does this by default -- it does not in all
>> versions; certainly fdisk did not -- 4k alignment is on our
>> deployment checklist, and we are manually checking
>> partitioning to make sure, when we are rebuilding boxes
I think it was when I was building a 6.0 box a couple weeks ago, but I'd
partition, it would do an mkfs... and *then* tell me it wasn't aligned,
and I played with it several times, and it absolutely would NOT align it,
nor offer to do so.


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