RAID reconstruction

[Mathew Snyder]

Phil Bettinson wrote:
> Romeo Theriault wrote:
>> On Dec 6, 2006, at 1:04 AM, Mathew Snyder wrote:
>>
>>> It has become necessary to reconstruct a hardware RAID from level 0
>>> to level 1.
>>>  This is attached to an Intel RAID card.  If I run the reconstruction
>>> will Linux
>>> automatically recognize the resized partition or will I completely
>>> bork things.
> 
> If you simply do it straight, I would guess that it would horribly bork
> your settings... having said that..... I've managed (by accident, using
> the Megaraid tools on RHEL3 64bit (don't do it, they don't work!))to
> reconfigure a RAID5 array of 6 250GB disks to a RAID 1 Array, and to
> find that Linux was quite happy, and even dealt with the new size. I was
> a little shocked as my main server all of a sudden gained a large amount
> of diskspace, but no redundancy, however.
> 
> I don't think I would ADVISE doing it straight. I think if you are going
> to be using a partition that is going to be growing in size you probably
> want to look at creating logical volumes, so you can grow and shrink
> them. Perhaps there's another way to achieve what you need doing?
> 
> 
> Thanks,
> 
> Phil
> 

As it turns out, I inadvertently went from a RAID 5 to RAID 0 and lost all of my
redundancy.  Incidentally, I did this with the MegaMGR tool  which seems to
function well with one exception.  There seems to be roughly 830MB of unused
space on the logical drive.  It won't let me add a drive to the array as a
result.  Instead, it requires me to create a second logical drive so I guess I
won't be getting my RAID 5 back.

I'm not concerned about the growth though.  The database that resides on this
server has only only grown to a little over 6GB in size and it's roughly 3 years
old.  My concern is redundancy.  Especially since this occurred as a result of a
failed drive (among other things, such as me not paying attention ;) ).

Mathew