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

On Wed, Mar 13, 2013 at 12:01 AM, Keith Keller
<kkeller at wombat.san-francisco.ca.us> wrote:
> On 2013-03-12, Arun Khan <knura9 at gmail.com> wrote:
>>
>> Software RAID is an option but I don't think hot swap is possible
>> without some tinkering with the mdadm tool a priori.
>
> Hot-swapping a failed drive is basically the same process AFAICT with a
> 3ware array or an md array.  The primary issue would be to make sure the
> controller supports hot swap, and how you tell it to release a drive
> from the kernel (a la tw_cli /cx/px remove).  And if you have one or two
> spares on a modest array then you can schedule site visits around your
> own schedule if a drive fails--either a hardware RAID or linux md will
> automatically rebuild with a spare when an active drive is marked as
> failed.
>
> Did you have other concerns about hot swapping?  I may be confusing what
> you're hoping to do.
>

I have no experience with hardware raid and what is entailed in "hot
swapping"  disks connected to HBA.

My expectation with hardware controller (that supports hot swap), (a)
is to identify which drive has failed (via an LED in the RAID cage),
(b) the local support guy removes that disk,  (c) inserts a new disk
and (d) the controller detects the new disk and adds the new disk into
the array  and automatically rebuilds the array.  Is this possible
with hardware controllers?

It looks like, even with a hardware controller, I would still have to
use the CLI tools to remove the failed disk and add the new one.
Please correct me if I misunderstood.

With a hardware controller, I was hoping the process of
removing/adding a drive would not involve CLI tools.

-- Arun Khan