Re: raid1 mysteriously switching to read-only

On Sun, Dec 11, 2005 at 11:29:23PM +0900, Yanggun wrote:

I did not find involved part with this in the document.

I am sorry, inform it is what section.

Basically, the md driver acts like another hard disk.  So a regular
setup looks like this:

---------------------------------
|				|
|	Applications (ls, cat)	|
|				|
---------------------------------
		|
		v
---------------------------------
|				|
|	Filesystem (ext3)	|
|				|
---------------------------------
		|
		v
---------------------------------
|				|
|	Block layer (sda1/sdb1)	|	
|				|
---------------------------------

and a software RAID setup looks like this:

---------------------------------
|				|
|	Applications (ls, cat)	|
|				|
---------------------------------
		|
		v
---------------------------------
|				|
|	Filesystem (ext3)	|
|				|
---------------------------------
		|
		v
---------------------------------
|				|
|	Block layer (md0)	|	
|				|
---------------------------------
		|
		v
---------------------------------
|				|
|	Block Layer (sda1/sdb1)	|
|				|
---------------------------------

The format of sda1/sdb1 is the RAID data that the md driver writes to
them.  It form a complete layer of abstraction between your
applications and the actual devices you are storing data on.

-- 
Ross Vandegrift
ross@lug.udel.edu

"The good Christian should beware of mathematicians, and all those who
make empty prophecies. The danger already exists that the mathematicians
have made a covenant with the devil to darken the spirit and to confine
man in the bonds of Hell."
	--St. Augustine, De Genesi ad Litteram, Book II, xviii, 37