hardware raid solutions?

[Eric S. Johansson]

Lea Gris wrote:
> Alexander Skwar a écrit :
>> David Abrahams schrieb:
>>
>>> Does anyone happen to know if hardware RAID is easier to configure
>>> than software RAID?
>>
>> It certainly is. In true hardware RAID, you configure the RAID in
>> the "BIOS". The operating system then only sees ONE drive.
> 
> In hardware RAID, the controler is a single point of failure. If the 
> controler dies and you can not find the very same controler 
> model/version you are lost in the wild land of unrecoverable 
> incompatible hardware raid setup.
> 

but there are so many ways to fail with all raid solutions.  You need to 
pick the failure you are comfortable with and build a recovery solution 
around that.

For example, with any raid environment, I use a good backup such as 
rsnapshot to make sure I have another copy of the data (and a little bit 
of history)

Software raid (mdX) does work well most of the time.  Unfortunately, I 
have had failures due to crashes, power outages etc. where the raid 
array doesn't reconstruct.  In raid 1, I was left with two discs that 
were different but neither was obviously bad and I couldn't tell which 
was the right one hence my move to raid five.

Software raid also has problems when you're doing anything disk 
intensive like backup every hour or two.  Yes, hardware has similar 
problems but is not my CPU that's being eaten alive.  :-)

So, convince me that I can use a software raid solution for my system 
for all partitions and still be able to boot if the raid array has 
failed (total failure, one disk, or 2 disk).

if I were to use software raid, I would break up the large disks (200 
GB) into 50 GB physical partitions, Raid physical partitions (from 
different disks duh), LVM the raid physical partitions together and then 
create logical volumes for all of my system partitions.

the reason for the strategy is that if rate needs to reconstruct, it 
will take less time to rebuild an individual partition than the entire 
disks.  If all need to be rebuilt, well it's part of a very painful 
experience.  ;-)

also convince me that there's a good notification process that something 
has failed.

I'm willing to be convinced.  Make your best argument for the software 
raid.  And failing that, hardware cards suggestions would also be 
welcome.  :-)