Re: Raid 10 chunksize

On Wed, 1 Apr 2009, Scott Marlowe wrote:
> On Wed, Apr 1, 2009 at 10:15 AM, Stef Telford <stef@ummon.com> wrote:
>>     I do agree that the benefit is probably from write-caching, but I
>> think that this is a 'win' as long as you have a UPS or BBU adaptor,
>> and really, in a prod environment, not having a UPS is .. well. Crazy ?
>
> You do know that UPSes can fail, right?  En masse sometimes even.

I just lost all my diary appointments and address book data on my Palm
device, because of a similar attitude. The device stores all its data in
RAM, and never syncs it to permanent storage (like the SD card in the
expansion slot). But that's fine, right, because it has a battery,
therefore it can never fail? Well, it has the failure mode that if it ever
crashes hard, or the battery fails momentarily due to jogging around in a
pocket, then it just wipes all its data and starts from scratch.

Computers crash. Hardware fails. Relying on un-backed-up RAM to keep your
data safe does not work.

Matthew

--
"Programming today is a race between software engineers striving to build
 bigger and better idiot-proof programs, and the Universe trying to produce
 bigger and better idiots. So far, the Universe is winning."  -- Rich Cook