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Re: "rock solid" motherboard

On Fri, Mar 11, 2005 at 02:43:47PM +0000, Paul Brook wrote:
> Most "sata raid" controllers aren't raid controllers. They're just normal sata 
> controllers with a fancy bios. The do not have any hardware raid 
> capabilities.

Works great as yet another sata or ide controller though.

> This is just plain wrong. I suggest you go and read some good documentation on 
> the properties of different RAID formats. Generally speaking RAID0 doubles 
> throughput for large writes as data is striped across both volumes, and has 
> seek times the same as a single drive. RAID1 (mirroring) usually gives 
> similar throughput to a single drive for large transfers, and a good driver 
> can reduce average seek times by reading data from whichever drive head is 
> nearest.

When would the heads ever not be in the same place on a raid1 setup?  I
would certainly be happiest if the drive always read both disks and
compared the reads to detect problems (but then again if it did, which
one of two different values would be correct?).  I would have thought
the heads were mostly in sync at all times.

> Not true. Read http://linux.yyz.us/sata/faq-sata-raid.html.
> Most (maybe all?) of the proprietary raid formats are supported by the dmraid 
> driver.

But is proprietary software raid ever faster/more efficient than linux
md raid?  And what if your board dies and you have to move the drives to
another machine, how do you get the raid back?  With md raid you just do

> Using a custom kernel is only a good idea if you already know what you are 
> doing, or absolutely need something not included in your distro kernel. Most 
> users are better sticking with the provided kernels as they then get the 
> security patching and testing done by the Debian kernel teams.

Yeah I have been sticking with Debian kernels for 2.6 since they have
provided most of what I need in a kernel.

Len Sorensen

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