[rescue] little low-wattage servers
J. Alexander Jacocks
jjacocks at mac.com
Mon Feb 6 16:52:29 CST 2012
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
> 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
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.
More information about the rescue