disadvantages of a linux cluster

[Donald Becker]

On Tue, 12 Nov 2002, Guy Coates wrote:
> > Can one elect to omit one or both disks?  Ethernet interface(s)?
> 
> Not as far as I know. The network interfaces are integral to the blade,
> though you could physically remove the disks if you wanted to.

There are configurations without disks.  We typically run our RLX blades
either diskless or with the disks spun down.

A previous posting implied that the reason the disks are slow is that
the are IDE.  That's not a reason.  The issue is that the disks are
laptop 2.5" drives, where the market wants low power, shock handling and
silence, not high transfer rates. 

These boxes are really designed for their initial market focus --
internet application servers and server consolidation.  They excell at
handling large numbers of network connections, with high performace
floating point and I/O being secondary.

> > Do the NICs do PXE?
> 
> Yup. The blades use PXE as part of their provisioning routine.  There is
> no reason why you should not be able to run the blades diskless.  (In fact
> the blades must be running diskless whilst they copy their OS image to
> disk after the initial PXE boot.)

Our system works unchanged in PXE diskless mode, and we were running
clusters of (old-generation) RLX blades as a over 1.5 years ago.  (I
can't figure out why it's suddenly newsworthy...)


-- 
Donald Becker				becker at scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Scyld Beowulf cluster system
Annapolis MD 21403			410-990-9993