[rescue] little low-wattage servers

[J. Alexander Jacocks]

On Mon, Feb 6, 2012 at 3:54 PM, Andrew Jones <andrew at jones.ec> wrote:

> On 02/06/2012 03:21 PM, J. Alexander Jacocks wrote:
>
>>
>> In the old days of having to purchase a VxVM (hp-ux/Solaris), or a
>> RAID-feature (DIGITAL UNIX/Tru64) license, hardware RAID was often
>> cheaper.  And, we didn't use to have the glut of unused CPU cycles that
>> most modern hardware provide.  So, hardware RAID controllers definitely
>> made sense.
>>
>> That was my whole argument.  Is that more clear?
>>
>>
> CPU cycles were never *really* the problem, even back when CPU time was
> expensive.
>
> It's cache consistency -- dodging the RAID-5/6 write hole, controlling
> data corruption.
>

Well, it does depend.  Sometimes CPU cycles really were the problem.  RAID
checksumming can put significant load on even a modern system.  I've been
there.

And true, making sure that the last bit of data gets written definitely is
important.  But, quite a few hardware RAID controllers don't do that
particularly well, either, especially those lacking a
battery/supercapacitor.  And, do you remember the hell of RAID vendor
batteries (Sun T3/T3+, for example)?  I surely do.  I'd much prefer to deal
with UPS vendors.

Anyway, all of this was just my opinion...take or leave it, as you choose.

- Alex