[Veritas-ha] Oracle & DRL
doug at eng.auburn.edu
Tue Jun 3 16:01:21 CDT 2003
On Tue, 3 Jun 2003, Andrey Dmitriev wrote:
> On Tue, 3 Jun 2003, Doug Hughes wrote:
> > DRL and oracle redo logs are for different purposes.
> > DRL is to make your mirrors resynch faster by logging what things
> > have been updated on which half (a redo-log of sorts at the vxvm
> > plex level).
> > DRL is discussed in the Veritas VxVM administration guide.
> For some reason, I thought there was a special case for DRL and
> Oracle. Now that I think about it, it doesn't make any sense. Maybe I was
> thinking about something else.
> DRL is just for mirrors, but is there are another level of logging that
> needs to be disabled for oracle datafiles, and enabled for redo logs,
> since redo logs contain all the needed recovery information for data
you want to make sure that kernel I/O buffering is disabled. This
is accomplished using Quick I/O, cached Quick I/O or ODM
(for VxVM/DBED 3.5 and Oracle 9i).
With 9i and DBED 3.5, nobody should really use regular quick I/O.
Cached Quick I/O is still useful for special purposes, but ODM
is the recommend way to go.
If you don't have DBED, you may be able to use regular ASYNC/IO
instead (see recent 2003 postings in the archive for more info).
That's all I can think of in relation to your query..
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