Re: Larry Ellison comments on Microsoft's benchmark

In the real world a DB2 EEE system on AIX would use IBM's HACMP for HA. If a machine/node fails, the DB2 instance on that machine fails over to another machine. The disk is multi-ported, like a cluster, to allow the second machine to access it. HACMP supports up to 32 node clusters.

On NT I suppose DB2 would have to use MS Wolfpack.

Ivana Humpalot wrote:
>
> "Neil Pike" <100577.553_at_compuserve.com> wrote:
> >
> > How can a single disk-subsystem be 12 times more reliable than
> > 12 disk subsystems? A logical or physical corruption here is
> > going to affect all OPS nodes.
>
> Yes, a corrupted disk will take affect all OPS nodes. However
> this is better than having 12 disks, and having your system go
> down if any *one* of those 12 disks is corrupted.
>
> If you have 12 disks as opposed to 1 then the probability of
> at least one disk going down is 12 times higer. So your system
> is 12 times less reliable.
>
> If you set the disk aside for a moment and look only at the
> reliability of the machines (and OS, especially in Windows land),
> then Oracle Parallel Server with the same 12 machines is INFINITELY
> more reliable than a DB/2 or MS SQL on 12 machines. Why? Because
> in Oracle Parallel Server, if one machine goes down the system
> as a whole is unaffected (except for lower performance.) Thus
> unless all the machines go down at the same time (very unlikely)
> your system is up. In DB/2 or MS SQL, if AT LEAST one machine
> goes down the system as a whole is down. If you have 12 machines
> then the probability of at least one machine going down is
> 12 times higher, so your system as a whole is 12 times less
> reliable compared to a system with only one machine. And if you
> compare to Oracle Parallel Server running on the same 12 machines,
> DB/2 and MS SQL are INFINITELY less reliable.
  Received on Thu Jul 06 2000 - 00:00:00 CDT