[CentOS] How to setup RAID 5 + 1 hot spare?

Thu Jan 24 14:45:44 UTC 2013
Ken godee <ken at perfect-image.com>

raid 6

On 1/24/2013 7:37 AM, Wenshan Ren wrote:
>
> Rudi Ahlers writes:
>
>> On Thu, Jan 24, 2013 at 7:59 AM, Ren Wen shan <renws1990 at gmail.com> wrote:
>>
>>> Hello everyone,
>>>
>>> I am new to this group so please forgive me if this question has been
>>> already asked.
>>>
>>> With four identical hard drives, I want to setup RAID 5 + 1 hot spare by a
>>> fresh CentOS (6.3) installation.
>>>
>>> I have read this article (
>>>
>>> http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-raid-config.html
>>> )
>>> and watched this video (http://www.youtube.com/watch?v=qm3MkuTfDLw), now I
>>> have the basic ideas.
>>>
>>> However, due to my limited experience and knowledge on this area, I am
>>> still confused.
>>>
>>> To make things easier, I only need a swap and a `/' partition.
>>>
>>> Could you give me any hint on this? What should I read to get the basic
>>> knowledge? How can I setup a simple RAID 5 + hot spare?
>>>
>>>
>>> Regards,
>>> - Meatball
>>> _______________________________________________
>>>
>>>
>> Since you're new to this list, and this topic, I'm going to spare you the
>> headache. Don't use RAID5 Even with a hot-spare, if you use large drives
>> chances are you'll loose everything if one of the drive fail and you need
>> to rebuild the whole set.
>>
>> Rather use RAID 10. The newer CentOS installation disks has an option to
>> setup RAID10, alternatively.
>>
>> There are numerous tutorials out there on how todo it, but this one seems
>> quite easy to follow:
>> http://www.youtube.com/watch?v=zlOK1voR2nA
>
> Hi Rudi,
>
> Thanks a lot for your reply, the video is very helpful.
>
> I read this discussion on serverfault.com
> http://serverfault.com/questions/106131/raid-5-with-hot-spare-or-raid-10-with-no-hot-spare
>
>
> but still quite confused as some people think RAID-10 is way safer while
> some people wrote:
> "
> I'd have to disagree with CHopper3. Since there are only 4 drives in
> this situation your failure capabilities are the same (2 drives) with
> either scenario, except with raid 10 if you happen to lose the wrong 2
> drives then you'll have a real problem. Also there is definitely an
> added benefit of having a global spare for your other RAIDs as well.
> "
>
>
> My new question is:
> As RAID 10 requires at least 4 hard drives (not very sure about this
> information), with only 4 hard disks, is RAID-10 without hot spare a
> better solution than RAID-5 + 1 hot spare? Why or why not?
>
> --
> Wenshan Ren
> Email: renws1990 at gmail.com
> Blog: wenshanren.org
> Douban: www.douban.com/people/renws
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