[asterisk-biz] Paranoia, Dell & 3CO

[Drew Gibson]

Bob Pierce wrote:
> On Tue, 2008-02-05 at 08:55 -0500, Steve Totaro wrote:
>   
>> I would go after RAID 5 and redundant power supplies.
>>
>>     
>
> I totally agree on the RAID 5 and redundant power supplies. It would be
> irresponsible not to get these.
>
> Bob
>
>   

Sorry to disagree, but RAID 1 would be far more responsible than RAID 5.

RAID 1 is for critical data and gives better protection at a higher 
cost. RAID 5 is for cheaper, bulk storage of less critical information. 
In addition, RAID 5 has lower performance and higher failure rate (more 
disks = more failures) than RAID 1.

Asterisk's disk storage is critical to the operation of a critical 
system and does not, generally speaking, require large amounts of 
storage. In fact, you would be hard pushed to find drives _small_enough_ 
to be right-sized for Asterisk!

Best practice would be OS and Asterisk on RAID 1 and, if you have a very 
high volume system (or you're into debug in a big way!), add some RAID 5 
for logging, recording, etc..

You'll be amazed how much quicker and easier it is to recover from a 
disk failure when the OS is still running.

I have seen several instances where a single drive in a RAID 5 set has 
suffered electrical failure and corrupted (or convinced the controller 
that it has corrupted) multiple, otherwise good, drives on the bus. Even 
taken out a hotspare at the same time. Think of it has an electrical 
fart onto the bus. I have yet to see the same thing happen with RAID 1. 
(and don't even think about asking how long I've been watching systems 
fail!) :-)

RAID 5 is great in it's place but why buy 3 drives when 2 will get you a 
better result?

regards,

Drew






-- 
Drew Gibson

Systems Administrator
OANDA Corporation
www.oanda.com

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