seth vidal wrote:
> On Tue, 2008-09-30 at 16:21 -0400, [EMAIL PROTECTED] wrote:
>   
>> I would love to use kickstart but my peers are directing me to use
>> images. The perception is that images would deploy faster than
>> kickstart. Has anyone on this list done any performance measurements of
>> images verses kickstart or just kickstart performance. For example there
>> is an old paper documenting system imager installing 1000 nodes in 15
>> minutes. I do not have the hardware yet to test performance but I may be
>> forced to use this method unless I can get numbers to back up my
>> decision.
>>
>> http://wiki.systemimager.org/index.php/BitTorrent#Benchmark
>>
>>     
>
> I think it really depends on your use case.
>
> For example. If you're imaging 1000 identical nodes all at once it is
> quite possible that a torrent-based imager will be faster.
>
> However, I'm willing to wager a lot of people here are not imaging 1000
> nodes all at once. They're install 5, 10, 15 servers at a time and want
> a consistent and repeatable install process that allows some variability
> w/o having to break your back to provide it.
>
> Hence, kickstart wins, hands down.
>   

Indeed. I know of one particular installation that was installing 
200-300 nodes at once and kickstart
was still rather zippy (15 minutes or so), without a mirror. Unless you 
are seeing time problems this way, I'd go
the kickstart route, and then if you /are/ seeing time problems then, 
come back, and there are a few ways to mitigate
that.

First off, install server mirror setup is especially easy in new 
cobbler. As an alternative
Cobbler also has the "--server-override" parameter so all systems can 
PXE off of one box and then
serve their content from multiple mirrors. This way you can, if you 
want, explicitly tell certain systems
to boot off a different http tree.

# establish a mirror on cobblerslave1
cobbler replicate --master=mastercobbler.example.org --full-data-sync # 
first time only, later use other flags
# establish a mirror on cobblerslave2
cobbler replicate --master=mastercobbler.example.org --full-data-sync # 
first time only, later use other flags

# set up a certain cobbler system to use mirror2, regardless of who 
actually serves it via PXE
cobbler system edit --name=foo --server-override=cobblerslave2

I have also seen simpler things done with just a squid cache or mirror 
of the install tree and some clever things in %pre
to decide which "url" line to use in the kickstart.

I am fairly convinced that the problems caused by dealing with images 
(not knowing what's in the image, needing to build it,
how do you rebuild it or build it when distributions come around, making 
it work with differences in hardware that the installer
would normally account for) are not worth dealing with in most 
applications.

With kickstart, you get the same advantages that a good configuration 
management system buys you -- you have a record of how
everything got the way it was and you can easily rebuild them and make 
changes.

With images also still transferring the image over the network, and the 
time spent to evaluate and process the kickstart is probably not that 
intensive.

Also with images it's easy to get in the habit of not updating them 
properly because they are "golden" which is a euphemism that really 
should not be used.

Especially in Fedora 7 and later (and should be in EL 6 and later), you 
can attach yum repos in kickstart and make sure you get all of your 
updates to all of your packages
at install time -- no more calling yum in %post.

--Michael


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