A sector size of 512 was assumed and hardcoded, causing dd to fail when
it tried to write in chunks smaller than the sector size for disks with
4096 bytes sectors. The size of GPT in sectors also depends on sector size.
Change-Id: Ide5318eb503d728cff3221c26bebbd1c214f6995
With the iscsi deploy long gone, these modules are only used in IPA and
in fact represent a large part of its critical logic. Having them
separately sometimes makes fixing issues tricky if an interface of
a function needs changing.
This change imports the code mostly as it is, just removing run_as_root and
a deprecated function, as well as moving configuration options to config.py.
Also migrates one relevant function from ironic_lib.utils.
Change-Id: If8fae8210d85c61abb85c388b300e40a75d0531c
