* Ethan Quach <ethan.quach at sun.com> [2007-10-29 22:39]:
> 
> Stephen Hahn wrote:
> >* Ethan Quach <ethan.quach at sun.com> [2007-10-26 22:46]:
> >>
> >>The BE utility is a command line utility which will replace the LU
> >>command line.  This new BE utility will provide the same general
> >>functionality as what LU provides wrt BEs ??? create, delete, list,
> >>upgrade, activate, mount, unmount - but with ZFS support. The main
> >>shift here is that we are moving users to a ZFS based system.  With
> >>Snap Upgrade, a user won't be able create UFS based BEs anymore, but
> >>their will be support to migrate users off of UFS BEs.
> >
> >  I would actually expect a BE utility to be only concerned with the UFS
> >  -> ZFS transition.  Every other operation appears to overlap with
> >  pkg(5)'s manipulation of linked and multiple images.  I'd rather see
> >  the "image-*" commands adjusted than introduce another tool.
> 
> I would agree that all pkg'ing and upgrade operations could fall
> entirely into pkg(5), but I don't think we can avoid a new tool
> altogether.  Other BE tasks seem generic enough not to be associated
> pkg(5).  For example, it seems out of scope to use pkg(5) to get a
> listing of all existing BEs and their properties, or to mount/umount
> a BE.

  pkg(5) has to list all of the images that are linked to a parent image
  already, so it already needs to have operations of this kind.  More
  importantly, the likelihood that the packaging operational history and
  the BE operational history are going to be be interesting to an
  operator is high.  Using a single public CLI makes this easier.

  (When would someone want to mount/unmount a BE outside the context of
  a tool?  If development only, then a private CLI should suffice.
  Even so, it would be easy to add this to the pkg(1) command.)

  I suppose my larger concern with the diagram is what it leaves out:
  zones.  The diagram hints that libbe will assist utilities with file
  system creation and snapshots, but omits zoneadm(1M):

  +-------------+ +-------------+ +-------------+ 
  |             | |             | |             |
  | installer   | | pkg         | | be utility  |
  |             | |             | |             |
  +-------------+ +-------------+ +-------------+ 

  +---------------------------------------------+ 
  |                  libbe                      |
  +---------------------------------------------+ 

  +-------------+ +-----------------------------+ 
  |             | |                             |
  | libtd/libti | |         fs operations       |
  |             | |                             |
  +-------------+ +-----------------------------+ 

  Perhaps more selfishly, it seems that pkg(5) can rely on libbe only
  for root filesystem operations, but must carry its own implementation
  of snapshot management for zone roots.  I don't believe this split is
  correct.

  - Stephen

-- 
sch at sun.com  http://blogs.sun.com/sch/

Reply via email to