On Sat, Dec 18, 2010 at 12:07 PM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote:
On Sat, Dec 18, 2010 at 13:25, Gaurav MahajanHopefully my simple idea would help:
<gauravmahajan2007@xxxxxxxxx> wrote:
> Hello all,
>
>
> I am trying to understand the code for raid1.c But I was
> not able to figure out the exact policies and protocols followed by
> the programmer . Can anybody tell me the policies like how data is
> recovered once default mirror is damaged or how mirror set is created.
AFAIK, RAID is now implemented via device mapper. Precisely, mirror
mapping. Thus, I suggest to lurk into device mapper code for further
research
Mulyadi,
Raid is separately implemented in both MDRAID and DM.
DM (device mapper) is the newer code base that was created for 2.6, but it is far less functional than MD.
ie. DM does not support raid 10, 4, 5, or 6. MDRAID supports all of those including multiple varieties of raid 10.
mdadm is the userspace tool for working with mdraid.
Both are actively maintained, but I'd say mdraid is by far seeing the most improvements. Neil Brown (with Novell/SUSE) seems to work on it nearly full time.
Greg
Raid is separately implemented in both MDRAID and DM.
DM (device mapper) is the newer code base that was created for 2.6, but it is far less functional than MD.
ie. DM does not support raid 10, 4, 5, or 6. MDRAID supports all of those including multiple varieties of raid 10.
mdadm is the userspace tool for working with mdraid.
Both are actively maintained, but I'd say mdraid is by far seeing the most improvements. Neil Brown (with Novell/SUSE) seems to work on it nearly full time.
Greg
