[dm-devel] LUKS2 - RAID0 - NVME : alignment issue

[Milan Broz]

On 18/10/2018 20:43, Mike Snitzer wrote:
> On Fri, Oct 12 2018 at  7:56am -0400,
> laurent cop <laurent.cop at gmail.com> wrote:
> 
>>    2) Is it normal to have low performances while writing with dd. I was
>>    using LUKS previously and I got only one dev mapper. Now I got 2. Does it
>>    have a big impact on performances?
> 
> This last question really makes me wonder: did you intend to enable the
> use of dm-integrity?

If you use an authenticated encryption in LUKS2, it must use dm-integrity as a backend,
so you get two stacked devices. (Authentication tag and random IV must be stored together
with every sector, here dm-integrity just provides a space for it, it does not
calculate anything, all is up to dm-crypt.)


m.