[DRBD-user] database on drbd

Lars Ellenberg Lars.Ellenberg at linbit.com
Sat Mar 6 16:46:17 CET 2004


/ 2004-03-06 05:39:08 -0800
\ abhin.g.s @ RASC:

> inconsistency was reffered to the "sync" parameter. That is if
> the sync is not applied after the transcation, it wont be
> written to the filesystem .. i read it somewhere, so oracle
> seems to use rawdevices. So is it required if i am going to run
> mysql, postgre sql or anything of that sort.

Which "sync" parameter?

If the application (database) does not flush its transaction
to disk, this is a BUG in the application. I doubt that there is
any transactional application that does forget about this.

And, as already stated, the "flush to stable storage" operation
does only complete, if it has reached stable storage on BOTH nodes
(with protocol "C", that is). 

I believe oracle (and others) use "raw" devices due to performance
reasons, because this way they can spare the filesystem overhead.

If using a filesystem could lead to database inconsitencies,
nobody would use it...

But anyways, there should be no problem using drbd as raw devices.
BTW, oracle has its own "clustering capabilities", iirc ...

	Lars Ellenberg



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