1 |
On Mon, Apr 05, 2004 at 06:41:47PM -0700, Julio Cazares wrote: |
2 |
> Raid also does not offer a better offering because it multiplies the |
3 |
> probability of failure 2 times. |
4 |
> |
5 |
> RAID, I believe it works best on their native "Quality" server design |
6 |
> and |
7 |
> manufacture: SCSI. |
8 |
> |
9 |
> Putting for example 4 IDE HD's In 2 RAID channels stressed the Power |
10 |
> supply (Chinese and consumer conceived also), and this probably lead |
11 |
> to |
12 |
> disaster on the long run. |
13 |
> |
14 |
> So, One SCSI, without RAID, is better (Thinking on probabilities), Due |
15 |
> to |
16 |
> the manufacture Quality assurance differences. |
17 |
> |
18 |
> It is the same reason because the airplanes are safer with less |
19 |
> motors, |
20 |
> (Contrary of the public opinion and feeling). Or in a car, Purchase |
21 |
> two |
22 |
> "Unbranded" tires instead of a new Michelin. |
23 |
> |
24 |
> Best Regards. |
25 |
> |
26 |
> Julio. |
27 |
|
28 |
Julio, |
29 |
|
30 |
I don't believe I understand your rationale for claiming that RAID is |
31 |
going to increase the probability of failures. If you consider the case |
32 |
where each drive alone has a a 10% chance of failing, two drives |
33 |
simultaneously failing should have a 1% chance of happening. This is a |
34 |
fairly great reduction in the chance of a critical data failure. |
35 |
|
36 |
Similarly, in a plane, virtually every control system is in some manner |
37 |
redundant (at least in my recollection -- I'm trying to recall the |
38 |
discussions on plane regulations and failure modes from my first year |
39 |
engineering class). This redundancy means that if one system fails |
40 |
there is another to take over and guide the plane to safety. Even if |
41 |
the systems are identical with a 1% chance of failure this reduces the |
42 |
probably of the plane becoming inoperable to 0.01%, or 1 in 10000 |
43 |
compared to 1 in 100. |
44 |
|
45 |
I can hardly see how this is increasing the chances of your plane |
46 |
crashing to the ground. |
47 |
|
48 |
Andrew |
49 |
|
50 |
-- |
51 |
gentoo-security@g.o mailing list |