Re: Best tool to partition Drives with new sector geometry - (WAS: Need Help with crashed RAID5 (that was rebuilding and then had SATA error on another drive))

[Benjammin2068 <benjammin2068@gmail.com>]

On 09/18/2016 02:17 PM, Wols Lists wrote:
>
> I'm sure you know this, but getting the physical/logical block size
> out-of-sync hurts disk performance. And copying a smaller partition into
> a larger allocated space is perfectly harmless. So...
>
> I'd simply use a modern partition manager (such as gdisk) to partition
> your new drives such that the new partitions are larger than the
> existing ones, and are properly aligned relative to the drive geometry.
>
> Then copy the old partitions across however you were planning - whether
> it's "mdadm --replace" or stopping the array and "dd old-device
> new-device" or whatever.
>
> If you've got a bit of wasted space, or whatever, who cares.
> You can resize your file-systems to use all available space, if you wish
> (can't remember how, whenever I've done that sort of stuff it hasn't
> been hard).
>
> But I'd certainly try and avoid those offset warnings - it smacks to me
> of a mismatch between 512-byte blocks and 4K disk sectors, and I
> wouldn't want the drive firmware messing about correcting mismatches
> between OS 4K blocks and drive 4K blocks. I don't fully understand it
> but I know there was a lot of grief with exactly this sort of thing in
> the transition from 512-byte to 4K.
>


Aha! That's what I needed to know.

I was wondering if I can make a partition (I think) that's 3/4 of a block larger (3072bytes) than the original /dev/sdX1's on the old HD103SJs drives.

You've answered my question perfectly.

I can use sfdisk or parted to get that done...

Thanks a bunch!

 -Ben