Proper alignment between disk HW blocks, mdadm strides, and ext[23] blocks

["Chris Worley" <worleys gmail com>]

How do you measure/gauge/assure proper alignment?

The physical disk has a block structure.  What is it or how do you
find it?  I'm guessing it's best to not partition disks in order to
assure that whatever it's block read/write is isn't bisected by the
partition.

Then, mdadm has some block structure.  The "-c" ("chunk") is in
"kibibytes" (feed the dog kibbles?), with a default of 64.  Not a clue
what they're trying to do.

Finally, mkfs.ext[23] has a "stride", which is defined as a "stripe
size" in the man page (and I thought all your stripes added together
are a "stride"), as well as a block size.

It's important to make sure these all align properly, but their definitions do.

Could somebody please clarify... with an example?

Thanks,

Chris