[CentOS] [OT/HW] hardware raid -- comment/experience with 3Ware

On 03/06/2013 12:28 PM, Keith Keller wrote:
> Please Note: 1) The default of the unit creation sets write cache
> to "on" for performance reasons.  However, if there is no BBU
> available for the controller, a warning is sent to standard error.

It is a warning that there is no BBU, not a warning that you'll get 
unsafe write caching without one.

To the best of my recollection, all controllers will turn off write 
caching if the battery fails and during the battery re-learn cycle.  If 
there is no BBU present, caching will never be enabled.

> Since we're already offtopic, I asked around about 3ware vs. MegaRAID.
> The ''consensus'' (1 < n < 5) was that MegaRAIDs had better performance
> but the CLI was daunting compared to the 3ware controllers.

I don't know whether or not there's any noteworthy performance 
difference.  MegaRAID cards have not been as prone to failure in my 
experience.  The management software is definitely inferior.

> But if LSI
> starts phasing out the 3ware line perhaps it makes sense for people to
> start looking at MegaRAID controllers to be prepared for this
> possibility.  (The minimal web searching I've done seems to support the
> dauntiness of the MegaRAID tools.)

Whether or not LSI continues to make 3ware cards, I continue to strongly 
recommend against their use.  They suck.  They have always sucked.  If a 
customer wanted me to manage a system with a 3ware card in it, I'd 
decline because at some point I'm going to be paged during off hours to 
fix the damn thing.