On 8/27/07, Dave Miner <Dave.Miner at sun.com> wrote: > I'm not sure I understand how you are intending to differentiate "end > users" vs. "sysadmins" but I'll assume the former are desktop/laptop > users and the latter are server administrators in corporate environments > and play it that way. > > I agree that LU is not something the average user will know about up > front, and I will agree heartily that it has a number of usability > issues. But I will strongly disagree as to who will find it useful. > > Once they've found out about LU, we find more "end users" taking > advantage of it than the "sysadmins". "sysadmins" at many environments > have standardized procedures (or, in some cases, superstitions) that > they've developed over the years and are leery of trying out something > that seems so radical. On the other hand, the average users say "I can > upgrade without downtime and without worrying about ending up with a > brick? Sign me up!" with little prompting, once they are educated about > it. The main issue both face, however, is that if they've already > carefully laid out their disks and didn't leave slices available, then > making the change is *very* disruptive and far less likely to occur. So > if we want people to adopt it, we need to make it the default.
I'm generally in agreement here - up to a point. At work, on pretty well all my systems LU is never going to be used. Systems tend to be rebuilt rather than upgraded; we have backups and recovery procedures if an upgrade ever went wrong. (I also have many systems that don't have enough disk space for LU anyway.) As a home user (or, more generally, standalone machines living outside a managed infrastructure), LU provides a useful safety net and is more relevant. So it's a good default. And those of us in managed environments are going to wipe them anyway, so the defaults should be biased away from datacenter users. (The up to a point bit: the issue goes away when you have ZFS and don't have to preallocate the space, so how much is it worth arguing over? And I still worry that in the UFS case you waste an awful lot of space - you need to allocate generously or it's not worthwhile, and the disks currently in the wild aren't that large yet that we don't have to be careful.) -- -Peter Tribble http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/
