[dm-devel] dm-verity usage help related

[Shivaramakrishnan Vaidyanathan]

Hello ,
I am new to dm-verity and I am finding it hard to use it.

This is my setup.On one VM running Ubuntu-12.04,I have a nfs-share
partition

on which I have virtual disk image files of other vm's.I want to perform
the integrity

check on these files/nfs-share.

My nfs-share partition (/dev/sdb1 mounted at /nfs-share) size is 10GB.From
the

documentation,I see the numbers 4096,4096,52224,1,root_hash and salt.

I know the doc says
4096 = datablock
4096 = hashblock
52224 = number of blocks
1 = hash offset



SIZE=$(blockdev --getsz /dev/sdb)

dmsetup create name -r --table "0 $SIZE verity 1 /dev/sdb /dev/sdc 4096
4096 52224 1 sha256 <root_hash> <salt>"

But my question how do I get these values for my setup? How do I know the
size

 of data block /hashblock in my case?How I calculate the number of blocks
and

root hash and salt to feed into the command.Can you please let me know the

process to get these values?

Also it mentions to use verity setup command for this purpose.Can you let
me know

the arguments or an example here?

Looking forward to your reply and help.
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