Author: W B Hacker Date: To: exim users Subject: Re: [exim] [OT] RAID (was: Re: Which hardware do you use foryour
installation?)
Ward Vandewege wrote: > On Thu, Jun 12, 2008 at 10:28:17AM -0400, Christopher Meadors wrote:
>> On Thu, 2008-06-12 at 10:20 -0400, Ward Vandewege wrote:
>>
>>> ... and if you buy a spare hardware raid controller of *every type you have
>>> in use*.
>>>
>>> That's the main disadvantage of hardware raid over software raid - if the
>>> controller dies, you're dead in the water unless you have a spare that's
>>> exactly the same type. With software raid, if the controller or box die, you
>>> just stick the disks in another box and you're on your way.
>> That depends on the controller, a lot of recent ones are using the Linux
>> on-disk format. So if the controller fails you can just throw the disks
>> in a Linux machine and still have access to your data.
>
> Examples please. This is interesting. I've yet to encounter a hw-raid
> controller that did not do proprietary - and model-specific - formatting of
> its drives.
>
> Thanks,
> Ward.
>
>
I have yet to encounter one that *did* so for SCSI and RAID1 - or
perhaps more accuratley, did so in a manner that interfered with
mounting the drives to another make of controller w/o need of a 'rebuild'.
OTOH, I'm partial to those using LSI chipsets. For most others I have
used 'duplexing' so each controller was not aware it was a part of a RAID.
But yes, almost every other RAID 'level' *except* 1 or 0 will vary in
(at least) how parity, ECC, et all are stored.
