[Beowulf] RE: A couple of interesting comments

[Greg Keller]

Gerry,

As a former installer/patsy at one of those nameless clumsy hardware  
vendors, I thought this *may* be useful for you:

1.  We specified "No OS" in the purchase so that we could install  
CentOS
as our base.  We got a set of systems with a stub OS, and an EULA for
the diagnostics embedded on the disk.  After clicking thru the EULA,  
it
tells us we have no OS on the disk, but does not fail to PXE.

Vendors get into all kinds of legal issues when they don't sell M$  
licenses they are supposed to have EULA's for cover.  They used to  
clobber/corrupt partion tables etc. when fdisk'd ruthelessly but are  
largely benign now if you handle issue #2 gracefully and get the  
standard install/fdisk launched.  The vendor I worked for had a EULA  
free sku but only if you purchased RHEL WS licenses.  Blank disks  
Always had EULAs.


2.  BIOS had a couple of interesting defaults, including warn on
keyboard error (Keyboard?  Not intentionally.  This is a compute node,
and should never require a keyboard.  Ever.)  We also find the BIOS is
set to boot from hard disk THEN PXE. But due to item 1, above, we  
never
can fail over to PXE unless we load up a keyboard and monitor, and hit
F12 to drop to PXE.

A fast trick I've used:
a. Keyboard errors are usually just complaint messages on a console  
you'll never see.  I haven't seen them halt a system during boot in  
years so hopefully this is cosmetic.
b. to get around keyboarding through the BIOS config, a system with  
hot swap drives can be simple:
        Eject the drives
        Boot the system (with ethernet cabled to a powered on switch)
	Wait long enough for the system to post and decide there's no hard  
drive, which bumps the PXE up to first boot
        Power down, reinstall the drives - Now PXE is the primary boot device

This sounds more painful than it is.  I've deployed a few 500+ and a  
couple 1200+ node clusters and life was much faster and simpler this  
way.
Note:  With many systems you can switch back to Disk as primary boot  
device by powering off the ethernet switch and going through the 2  
boot dance so the local drive becomes the primary boot device again.   
We normally setup PXE to tell the node to boot local on the occasions  
we need a stateful install.  YMMV

Once the nodes are booted you can script the "Config" utility from the  
vendor to tune the bios/bmc etc to your preferred favorite settings.   
I use Perceus so the local drives are always scratch+swap space and we  
partition them and format on the way up if they need it.

Hope this helps,
Cheers!
Greg
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