Chris Rijk wrote:
> Late reply time...
> 
> 
> dminer wrote:
>> The usability issues with WAN installation are a priority to fix; our
>> current support for this is way too hard to set up on the server side.
>>
>> What I see is that there are tradeoffs to be made by each user. In
>> section 4.1.8 of the paper, I broke down the performance into three
>> broad categories, synopses of which were:
>>
>> 1. download & burn media
>> 2. start the installer and provide any inputs
>> 3. lay down the bits and get them running
>>
>> A Sun-provided WAN installation service minimizes #1, while increasing
>> #3 (and perhaps #2); overall it should be the fastest option for a
>> single install, and as WAN speed and reliability increase it seems the
>> advantage will widen. Avoiding burning also minimizes #1 to some
>> extent. If you're going to do more than a one-off install, you're
>> better off creating a cache on the local LAN, so that you optimize #3.
> 
> I agree that for wall-clock time, WAN installation should be fastest
> (for a single once-off install).
> 
> For users who don't have an alternative machine they can use while
> installing Solaris, they are most likely to want to download Solaris
> in the background while using the machine - today they would download
> and burn to CD/DVD. In other words, what they care most about is
> system downtime, not end to end install time.  WAN install could
> easily take 5 or more hours, unless they have unusually fast
> networking. I think this would be typical for someone installing at
> home - eg an enthusiast or developer without access to a spare machine
> they could use at work.
> 
> In such cases, being able to install off an existing partition on the
> HD (or from compact flash) instead of DVD would be nice.
> 

I agree with all of your thoughts here, Chris.  One thing I should note 
is that internally to Sun, we do a form of this already, and have for as 
long as I can remember.  As each Solaris build is released, each of our 
engineering sites has at least one netinstall server which retrieves a 
copy of the image as a cpio archive using ftp and validates/unpacks it 
locally - it's the same result you'd get if you downloaded an ISO image, 
did the stuff to mount it as a lofs, and then ran setup_install_server. 
  Then each of us does our upgrades as we see fit; using Live Upgrade 
limits the downtime to the 5 minutes or so a reboot takes.

I think we'll move beyond just providing .iso's as the only public 
download option (flash archives perform much better, for instance), but 
I need to get release engineering and other parts of the process to buy in.

> btw, as a side-note, currently Solaris's installer doesn't seem to
> handle CD/DVD burn errors very well - if the checksums fail, it just
> seems to carry on. I've had this in the past, and a friend of mine got
> this recently when installing Solaris 10 for the first time.
> 

Yeah, known issue.  Marketing's been asking for us to do something, it's 
part of what's meant by #12 in my requirements list.

> 
>>> When you say "duty cycles for flash drives aren't quite up to hard
>>> drive standards", do you mean the number of re-writes Flash cells can
>>> handle without errors? If I recall correctly, Flash cells can
>>> generally handle many billion re-writes on average, and also has
>>> support for offlining groups of cells in a similar way to how hard
>>> discs handle bad sectors. Sounds like you have looked at this more
>>> closely than me though. btw, wouldn't ZFS's copy-on-write help a bit
>>> by spreading the writes around...?
>>>
>> I can't say I've looked at it that closely, my info is secondhand. We
>> certainly have hot spots in the system which would make me skeptical
>> that it's a good idea right now. ZFS might help, I guess, though I
>> don't think it was explicitly designed for this purpose so it's more a
>> side-effect than intentional, and thus seems likely to not be completely
>> effective.
> 
> Hmm, I note that Sun's new Netra CT900 has support for compact flash,
> but I can't seem to find more info. If it's good enough for 5-9s
> telco, it's probably good enough for general use.
> 

It has slots, but I don't know if you can boot off of them.

Dave

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