[CentOS] measuring kernel speed

[Ross Walker]

On Mon, May 10, 2010 at 1:15 PM, Les Mikesell <lesmikesell at gmail.com> wrote:
> On 5/10/2010 11:37 AM, Ross Walker wrote:
>>
>> I have ESXi hosts here running 20 VMs per host with some doing
>> terminal services, some doing email, some doing database and other
>> network services and I have not noticed any diminished performance,
>> and yes going virtual is simply the easiest way to perform upgrades.
>
> I think it is unfortunate how difficult it is to back up a working linux
> machine and restore it onto different hardware, given that the system
> really is very hardware independent.  But, detecting the hardware and
> mapping it to device drivers seems to be a black art hidden inside of
> anaconda and then the local hardware related settings are fairly
> hopelessly intertwined with application and user preferences in your
> backup copies.  I always thought that this would be a common enough
> problem that some distribution would address it, but so far it hasn't
> happened.

That's why God invented the systems administrator!

Here I use kickstart scripts for baseline server types that perform
all the basic configurations on install. Then I typically keep the
server-centric config in a common location, /etc/<servername> and use
symbolic links to the system supplied config, this can also be
scripted for quick recovery. I keep the application data on separate
volumes then the OS (typical OS image is 8GB, most is swap) using
iSCSI so I can connect to them from another VM easily enough (RDM or
direct iSCSI), everything is installed via RPM, if the distro repo
version isn't adequate I build my own and keep a custom in-house repo,
no third party repos.

I have yet to look at Cobbler which is suppose to simplify the
creation and management of all these kickstart scripts and provide a
nice interface, but haven't had the time yet.

If I am setting up an ESXi infrastructure the first thing I would do
is setup a Cobbler server and a Windows deployment server (maybe a
Solaris Jump Start server) and integrate it with the VMware vCenter
templates. Then it's all point-n-click server deployment from there.

-Ross