David W. Hodgins a écrit :
On Thu, 09 Jun 2011 09:33:23 -0400, Doug Lytle <[email protected]> wrote:
I've purchased a Hitachi 3TB drive that uses 4k sectors.
The drive is using 4k physical sectors. Is it using 512 byte logical
sectors or 4k logical sectors?
If it's using 4k logical sectors, you don't have to worry about
alignment.
If it's using 512 byte logical sectors, then you have two things to do.
Ensure partitions are aligned on 4k boundaries.
Use a gpt partition table, instead of a msdos style partition table,
as the msdos partition table cannot address anything beyond 2TB, due
to the use of 32 bit sector numbers.
A gpt partition table is also more secure, with a backup table at the end of
the disk.
Gpt typically has 128 partitions, all primary. Gpt doesn't have secondary partitions, thus
avoiding the associated daisy-chaining. Additionally, a gpt table takes less space than the
equivalent mbr format with secondary partitions.
I'd use gparted to partition the drive. In gparted, select Device,
Create partition table, Advanced, and use the drop down button to
select a partition table type of gpt. This creates a msdos style
mbr with a fake 2TB partition, so that older partitioning tools
like fdisk won't see any free space, and uses the guid partition
table to store information about the real partitions. See
http://en.wikipedia.org/wiki/GUID_Partition_Table for details.
I think gparted will default to aligning the partitions on 1MB
boundaries, which is a multiple of 4k.
That is my understanding as well.
After you've partitioned the drive with gparted, you may be able to
use diskdrake to specify the mount points, and create the fstab
entries, but I'm not sure if it will work with a gpt partition table,
as I've never tried it.
It would be much _safer to simply edit /etc/fstab to change the mount points. (Creating any
corresponding folders as needed.)
You _could_ use diskdrake to specify the mount points, but it is very risky to
do any other changes.
When I tried some other changes with Mandriva 2010.0, it corrupted the partition table -- every
time. (I didn't realise the cause until I specifically tested for corruption.)
I had to boot using systemrescuecd, and use gdisk on the cd, to repair the
partition table.
(If you procede carefully, gdisk, now in Mageia, is a useful tool for gpt disks, much like fdisk
for mbr disks.)
Regards, Dave Hodgins
--
André
