4K sectors on the drive, bigger sectors for geli and newfs?

[Christian Baer]

Hi folks!

A few days ago I installed a new drive that I would like to encrypt with
geli. It's one of the new ones with 4K sectors which means I have to
partition it differently than the older drives I have.

What I did so far:

  gpart create -s gpt /dev/ad6
  gpart add -b 2048 -t freebsd-ufs /dev/ad6

That should align the partition correctly.
pjd wrote in a post, that geli uses more than one key for larger file
systems, so I am quite happy to create a single (2TB) partion and file
system.

Due to the nature of the files that will mostly be stored on the drive
(digital photographs in raw format), my newfs will look something like
this (my idea):

  newfs -L raw -O ufs2 -U -f 4096 -b 32768 -i 2097152 /dev/ad6p1.eli

An inode every 2^21 bytes should do fine. Most of the files on the drive
(I expect something like 90%) will be 7MB or larger.

Any objections so far? Would it make sense to make the frags and blocks
even larger?

Considering that, I'm wondering how to init geli, especially using the
-s option.

  geli init -e aes-xts -l 256 -s $NUMBER /dev/ad6p1

It stands to reason that $NUMBER should not be smaller than 4096 bytes
since the drive itself doesn't have anything smaller to offer. :-) What
would be a good value? 4096 or 32768 or something else? What does this
default to?

Best regards,
Chris