[arch-general] 4k sector drives

Mauro Santos registo.mailling at gmail.com
Fri Apr 30 14:08:04 CEST 2010

On 04/30/2010 10:13 AM, Thomas Bächler wrote:
> Am 30.04.2010 01:37, schrieb bardo:
>> Parted automatically warned me about an unoptimal sector alignment
>> when I tried to put the first partition at 0 (the first partition
>> should start at 2MB), but if you want to be extra-sure just check the
>> the '-a optimal' parameter. About the disk reliability I can't tell
>> much, but I already transferred some 100GB to it, and of course I had
>> the first RAID5 build, which took a few hours and ran through the
>> whole disk. Also, smartctl doesn't have anything bad to say.
> I'm still curious about the status of 4k support in the latest
> util-linux-ng's (c)fdisk. Did anyone try that?

>From my tests not too long ago cfdisk does not play well with the
current 4K sector disks, at least when they report a 512B sector size as
is the case with the WD EADS disks. It also seems (to me) that cfdisk
will not play well with partition schemes that are not created in
"compatibility" mode so unless it gets updated it will soon be a
nonstarter for disk partitioning.

fdisk will align all partitions if you start it with 'fdisk -uc' and
accept the suggested partition start and use +***M to specify the size
of partitions, I didn't try specifying the end in sectors and check what
it would do to the next partition though. I have tried this with an
external WD Elements disk and fdisk. If using the whole disk with one
partition, fdisk will set exactly the same start and end sectors that WD
uses in the partition they define and format in the factory.

I did not try parted but I've read that it will also align the
partitions properly, but it may require some extra switch to disable the
alignment to cylinders.

Mauro Santos

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