Re: Raid 5 Array

[Marcus <nexuslite@gmail.com>]

Okay it seems to work now. I destroyed md0 and recreated it and then
just added it to the md2 array without doing any partitioning like I
did all the times before. Even when I created my old array I
partitioned it but mdadm destroyed the partition automatically.

On Sat, Apr 2, 2011 at 4:06 PM, Marcus <nexuslite@gmail.com> wrote:
> I am running a raid 5 only. The raid 0 is to make a number of smaller
> drives larger. Because a raid 5 takes the smallest drive and applies
> it to all drives.
>
> The original raid started off as a 26GB raid 5 with a 13GB, 40GB and a
> 160GB drive and I have grown it from there to its current size which
> is 1TB.
>
> I bought another 1TB drive yesterday and am trying to combine a 500GB
> and a 250GB drive to make a 750GB drive so I can push the raid up
> again this time to 1.5TB.
>
> The last configuration was a raid0 md0 320GB (160GB, 160GB), raid 0
> md1 570GB (md0, 250GB), raid 5 1TB (md1, 500GB, 1.0TB) which has been
> extremely stable for the last 3 months but ran out of space.
>
> The configuration I am trying to achieve is raid0 md0 750GB (250GB,
> 500GB) , raid 5 md2 1.5TB (md0, 1.0TB, 1.0TB)
>
> This started out as an experiment to see if I could do a raid 5
> system. It was originally built with drives I had laying around the
> house. Now it is big enough that I have started buying drives for it.
> I have gone through many configurations of extra drives to get it
> where it is now. I have had 1 catastrophic failure since I started and
> that was the last time I made it bigger. I was running on 2 drives one
> of them being the md0, md1 configuration and mdadm got confused and
> couldn't put md0 and md1 back together to have 2 working drives. I
> probably could have corrected the problem if I knew what I know now
> but as this is an experimental raid it is a learning process.
>
> The current problem I am having is every time I try to apply the 750GB
> raid drive to the raid 5 it corrupts the headers and 1 of the arrays
> report the wrong size. Which causes it not to mount. The only way to
> correct the problem seems to be to unplug the two drives that make up
> md0 and reboot onto 2 drives then start the process again. I am
> currently working on my 3rd attempt to integrate the 750GB raid drive.
> Each attempt takes 4 hours to restore the drive so it has been a long
> process. I haven't lost the data yet though so I guess I will keep
> trying. Hopefully it won't be too corrupt when I am done.
>
>
>
> On Sat, Apr 2, 2011 at 3:04 PM, Roberto Spadim <roberto@spadim.com.br> wrote:
>> why use raid 5,6? raid1 isn´t more secure?
>>
>> 2011/4/2 Roman Mamedov <rm@romanrm.ru>:
>>> On Sat, 2 Apr 2011 22:45:58 +0100
>>> Simon Mcnair <simonmcnair@gmail.com> wrote:
>>>
>>>> One last thing.... I've never heard of anyone using a raid 05. Why
>>>> wouldn't you use a RAID50 ?  Please can you dish the dirt on what
>>>> benefit there is ? (I would have thought a raid50 would have been
>>>> better with no disadvantages ?). I thought that raid10 & 50 were the
>>>> main ones in use in 'the industry'.
>>>
>>> RAID5/6 with some RAID0 (or JBOD) members is what you use when you want to
>>> include differently-sized devices into the array:
>>> http://louwrentius.com/blog/2008/08/building-a-raid-6-array-of-mixed-drives/
>>> --
>>> With respect,
>>> Roman
>>>
>>
>>
>>
>> --
>> Roberto Spadim
>> Spadim Technology / SPAEmpresarial
>>
>
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