[CentOS] [OT] Building a new backup server

[Keith Keller]

On 2013-11-04, John R Pierce <pierce at hogranch.com> wrote:
> On 11/4/2013 9:30 AM, Les Mikesell wrote:
>>> Besides, if you have a problem with a truly humongous RAID, the rebuild
>>> >will finish sometime around next summer....
>> Yes, I'd probably use a RAID10 style RAID so it runs at full speed
>> even with a drive out of the array so you can put off the rebuild
>> until a weekend.   A rebuild will keep the heads too busy to do a lot
>> of other work while it is running.
>
>
> Using a common LSI Logic Megaraid card (9260-8i, I think, but don't 
> quote me), and 11 by 3TB raid6 with hotspares (using Seagate 
> Constellation.ES2 SAS2 drives), single drive failure rebuilds took 24 
> hours, double drive failures took 36 hours, this with the system online 
> but mostly idle the whole time.  yes, if you have steady user IO 
> activity going on the rebuild would take quite a bit longer, as it only 
> proceeds when the disks are idle.

The MegaRAID controllers have a configurable rebuild rate.  The default
is 30%, but you can increase it up to 100% (which will probably kill
your system IO).  LSI 3ware controllers are also configurable in a
similar way (their scale is only 1..5).

--keith

-- 
kkeller at wombat.san-francisco.ca.us