what raid controller?

[John Hubbard]

Eberhard Roloff wrote:
> Willy K. Hamra schrieb:
>> Eberhard Roloff wrote:
>>> Willy K. Hamra schrieb:
>>>> uriah heep wrote:
>>>>> I would like to set up mirroring on 2 sata WD hard drives.  Could any one
>>>>> suggest a good low cost controller.  This is for a home computer not
>>>>> business.
>>>>>
>>>>>
>>>> before getting a controller, many current mother boards support RAID,
>>>> you sure yours doesn't? what's its model?
>>>>
>>>>
>>> This imho is dangerous advice.
>>>
>>> Imagine you use the "internal fake raid" controller. Let's say, three 
>>> years from now, your motherboard will fail. Usually, not a big deal 
>>> but you will surely not be able to buy a motherboard with the same 
>>> fake raid controller, then. Now what happens to your fake raided data?
>>>
>>> Well, it will be on your backup tape, if you are lucky...
>>>
>>> As drever things are, this advice is mainly targeted at Windows users 
>>> but even with Linux I would never ever touch such a mess for raid 
>>> purposes.....
>>>
>>> Kind regards
>>> Eberhard
>>>
>>>
>> i only tried RAID once on a dg965wh mobo using windows a couple of years
>> ago, and decided i'm no expert in it and returned back to IDE.
>> so basically such a RAID is also a fake RAID? i thought this is a
>> hardware RAID because it's set up before windows boot up, and before i
>> even see the intel splash screen. so it's not hardware?
>>
>>
> well, any non software raid is hardware, just by definition. ;-))
> 
> Now fake raid are at least part of made of software. As I see it, fake
> raid is any non removable raid adapter that does not have his own bios
> but relies on a (mostly) propriatary driver to work, instead.
> ex. in order to install windows on "fake raid" you need to prepare a
> special "raid driver disk" in order to make that work.
> In contrast, on a real raid, you get a raid bios where you arrange
> your disks to your likings and the OS will see just the disks you
> configured in the raid controller as being singular, physical disks,
> afterwards.
> 
> Again from my view, the main disadvantage is not the driver (assuming
> that this will be available for any existing and future operating
> system that needs to run there). ok, this is a major disadvantage in 
> itself, to. ;-)
> 
> It is more the incompatible data format that causes trouble when you
> are in a situation where your mobo is dead, but not available any
> more. Now imagine how quickly hardware changes and my conclusion is:
> Either "real hardware raid" or software raid and you are safe.
> 
> The very few times that I installed used fake raid were on windows 
> with Raid 0, meant to get as most power from the disk as possible for 
> hardcore gaming purposes. But this is another world, not mine....
> 
> kind regards
> Eberhard
> 
> 
Couldn't the same argument be made about the failure of the hardware 
raid controller?  Will it still be available 3 years from now?  Will you 
be able to get your data off of the array?  Are you sure that whatever 
format it uses will be supported by what every device you try to replace 
it with?

-- 
-john
There are only 10 kinds of people,
Those who understand binary and those who don't.