[dm-devel] dm-verity usage understanding
Shiva
shivaramakrishnan740 at gmail.com
Fri Apr 4 19:00:32 UTC 2014
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.
I have virtual disk image files of other vm's in this share.
I want to perform the integrity
check on these files/nfs-share at block level.
My nfs-share partition 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 k
now the arguments or an example here?
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