Regarding FAQ #20: performance with loop-aes and lvm

[Thomas Braun <thomas@xxxxxxxxxxxx>]

Hi,

as I am building a new server I want to use loop-aes (like the last years) for 
all partitions on it.
My current idea is to use for the HDDs (4-5) the following structure :
RAID6->lvm->loop-aes->xfs.

If I understood the FAQ entry number 20 from 
http://mareichelt.de/pub/texts.loop-aes.php#faq20 correctly this works 
without any problem. Actually I have already tested this setup in a virtual 
machine.

Regarding performance the post, 
http://mail.nl.linux.org/linux-crypto/2008-11/msg00033.html, suggest to use 
the command line 'lvcreate -i N' to create the logical volumne.

Reading the lvcreate manpage gives:
###########
-i, --stripes Stripes
              Gives the number of stripes.  This is equal to the number of 
physical volumes to scatter the logical volume.
###########

Without much thought I tried to use the --stripes option on my RAID6 in the VM 
but it failed with the message:
###########
Number of stripes (5) must not exceed number of physical volumes (1)
###########

So what does this mean?
Do I have to switch to a different RAID level (e.g. RAID10) to get a more 
multicore-using loop-aes system?
As far as I understand every loop-device has one process/thread/whatever to do 
the encryption, right? Therefore on a multicore system you should have more 
loop devices in use to get more troughput ?

Thanks for your time,
Thomas

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