On 01/28/2010 04:17 PM, Greg Freemyer wrote:
On Thu, Jan 28, 2010 at 4:38 PM, Carlos E. R. <robin.listas@telefonica.net> wrote:
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On Thursday, 2010-01-28 at 09:12 +0100, Per Jessen wrote:
FYI, mdraid will do that too, no big deal. Isn't that the whole point? I think the primary difference between the two is that mdraid takes up CPU cycles doing the mirroring, dmraid does not.
Both do, AFAIK. Motherboard, bios raid, is not a real hardware raid, it needs a driver that does the real work in the cpu, with some help from the chipset. That's why it is called "fake raid".
- -- Cheers, Carlos E. R.
I don't know the specifics, but mdraid for sure and possibly dmraid have been getting updates in the last year or so to offload the parity logic. I assume that some raid cards now expose their xor engine and thus the data blocks can be sent to them to handle the xor logic.
The patches I noticed were for IBM hardware iirc.
I think the really big difference between dmraid and mdraid is compatibility. MS Windows only supports the equivalent of dmraid, so if you want to create a dual boot raid system, you need to go that way.
If Windows is not a concern, I think mdraid is the obvious choice but there may be some subtleties I don't know about.
Greg
Right you are Greg, There has been an incredible amount of work done on dmraid in the past 6-7 months. RedHat maintains the code and there have been 4-5 major releases since August. The only pickle was whether you needed to add (or not add) a single 'p' at the end of the device mapper ID. In the dmraid 2.0.x flavor - the 'p' is there :p -- David C. Rankin, J.D.,P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org