[CentOS] RAID5 or RAID50 for database?

[Linux]

On Fri, May 23, 2008 at 8:28 AM, Guy Boisvert <boisvert.guy at videotron.ca> wrote:
>> And stick with md-raid 10 (also known as software raid) because it is
>> much more intelligently designed than any
>> closed-source-embedded-raid-controller.
>
> "More intelligently designed" -> Could you please tell us more on this one?

Simple answer: Open Source (and for a long time) I guess you know what
it means. But I wander if source of Adaptec raid controller's firmware
is opened in recent years.

>> Nowadays hardware raid frightens me because of the need to have spare
>> raid-controllers for every hardware-raid-configuration I have. They
>> are neither interchangable nor easily recoverable.
>>
>> md-raid 10 can be established with any number of disks (at least 3 but
>> better check with google)
>
>
> Not easily recoverable?  I did recovery many time without a hitch (Adaptec,
> 3Ware, LSI, PERC)!

Try recovering 3Ware failed disks with Adaptec then. Nearly every
vendor has his own way in details. Yes, mostly documented but not
interchangable. And I do not mean only RAID-1.

> As for RAID 10 with 3 disks, mmm... go see:
>
> http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

mdadm Raid-10 is neither 1+0 nor 0+1. So 3 disks is enough to supply a
minimum level of redundancy. You should have 2 copies of each stripes
on either 2 of 3 disks. But in 3 disk configuration loss of 2 disk
means total loss. Go check with man mdadm.

> Lastly, it's kinda strange that your name is "Linux": Maybe you're young and
> your parents decided to honor this great OS!  Well, i may name my next
> children "Cento" !!! ;-)

Well, my parents taught me understanding what I read better than you
(although I'm not a native English speaker)

> Hey, have a nice day "Linuxito" !

Thanks buddy.

And for referance, try reading this [1]

I do not want to start a flame, just sharing my experience with
different hardwares. This comparison about software-hardware raid
excludes SAN and other external RAID solutions. Externally attached
storage is outside the scope of this discussion. Externally connected
solutions can obviously be SAN, software RAID, hardware RAID, or a
combination thereof. [1]

[1] http://linux.yyz.us/why-software-raid.html