[Asterisk-Users] Hardware for Asterisk

[Andrew Kohlsmith]

> Have you experienced a hardware failure yet that you had to come back
> from? If you loose a drive, it is a high probability that you will loose
> the controller. So unless you have a add on card, or some motherboard

Yes, many times.  I have _never_ lost a controller when the drive went; the 
drive failures were all mechanical, not electrical, or not electrical to 
the point of causing the controller to die as well.

> with 4 IDE ports, you will corrupt the second drive of a mirror. If the
> second drive is corrupted, then you are only a hair above not having
> anything. If you don't trust that, check out the GOOD IDE raid
> controllers. You are only allowed to place 1 drive per port, and they
> only use 1 port on a IDE controller.

If you're using two drives per channel for IDE RAID you're just asking for 
trouble.  One drive per channel.  Lose a drive, it's _very_ unlikely that 
you will lose the _other_ drive.

> I don't buy it that any truly redundant raid system is as fast in
> software as in hardware on a machine doing anything significant. In raid
> 1, you are double or more writing all data to the drives. in a read
> environment, it might be able to share the load out to more than 1 drive
> and help, but I don't expect it would be much better than a dedicated
> controller handling the load. Any load of a software raid solution takes
> processor time away from the processes it is trying to complete. So take
> our VoIP application, if I am spending time getting the voice recording
> to 2 or more drives and the software to get it there, you have
> significantly reduced the amount of time available to the CPU to handle
> the VoIP packets in a timely manner. This only gets worse as call volume
> goes up. If it is hardware raid, you know it will be a single write and
> the controller deals with the problems.

I agree that software RAID of any kind adds load to the system.  I never 
stated otherwise.  I _did_ state, however, that if you're speccing a system 
and the system load is approaching a level where adding software RAID1 
gives you appreciable load increase, you are speccing your systems far too 
tightly.  The additional write to another drive channel for RAID1 is 
practically inconsequential for most systems, IMO.  RAID5 with a failed 
system, yes you do suffer _significant_ performance loss, but I wasn't 
talking about software RAID5...  :-)

> On server hardware, Dell has their own boards. IBM had their own boards.
> Compaq and HP also produce their own boards. Maybe they don't produce
> their own boards in the desktop models, but they do in the server class
> machines. While you can buy Intel, Tyan, and SuperMicro boards, I
> wouldn't consider any of the remaining ones you list as truly server
> class.

I stand corrected; I was under the assumption that Dell was farming their 
customized motherboards out to a standard OEM.

> Maybe not by default, but if you get into the hot swap PSUs you
> absolutely are talking quality.

Agreed.

> While I'll agree that a complete spare is a good idea, if you are
> looking for the bargains now, I don't have faith that you would also be
> the person who would buy 2 and leave the second untouched until failure
> occurs. I'll admit I couldn't leave a fully functioning machine just
> laying around not doing something.

:-)  I'm not much of a bargain-hunter when it comes to stuff that Must 
Work<tm> -- the bean-counters will bitch but when the system goes down for 
whatever reason and I can have it back up almost immediately it is worth 
every penny to them.

Regards,
Andrew