IBM BladeCenter Reliability/Availability Evaluation

August, 2007 2007 Clabby Analytics

Page 6 

Without a second power path, any failure along a power plane can bring down several servers. HP can

stack 16 blades into their chassis. This means that potentially 16 server could crash. Because IBM s

chassis has a second power path, if one power backplane fails, the other can be used to deliver continuous

power resulting in none of IBM s 14 servers crashing. In high availability environments, this could prove

to be a very big deal&

Dual Solid-state Disks and Tightly Integrated External Storage

IBM offers an impressive array of storage products that can serve its blade

architecture. These products include diskless blades, solid-state disks, flash drives,

local hard drives, highly-integrated external hard drives, and even SIO (serial

input/output) devices. But two of these devices/approaches were of particular interest

to Clabby Analytics: the stateless solid state drives, and the work IBM has done to

tightly integrate diskless blades with its DS 3200 dense storage family.

The reason I found these products so interesting is that they:

1.   Reduce power draw (and thereby reduce heat production) within blade

enclosures; and they

2.   Remove mechanical parts from within a blade chassis (reducing potential

mechanical failures while increasing overall availability and reliability).

My personal philosophy is that anything that can be done to reduce power draw from

within a blade chassis as well as anything that can be done to remove movable

parts on a blade represents goodness . By reducing power draw, the amount of

heat that a blade produces is reduced. And by reducing heat within a blade enclosure,

blades cost less to cool and blade components can last longer. Further, by moving

mechanical devices out of densely populated blades, maintenance is more easily

accomplished. (Note: HP offers dual, hot swappable mechanical drives that are easily

accessed and swapped within their blade environment. But I would argue that moving

those drives to an external location is a better design for the above mentioned

power/heat considerations).

A closer look at IBM s recently released dual-stacked solid-state drives (SSDs) reveals

that IBM is able to put two 16GB flash SSDs into a custom carrier that can snap into

and existing blade HDD (hard disk drive) casing (see Figure 4).

Figure 4 IBM s Dual-stacked, Solid State Drive Designed for IBM Blades

 

 

 

 

 

 

Source: IBM, July, 2007