From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wim Coekaerts Date: Wed Jul 6 13:04:16 2005 Subject: [Ocfs2-devel] 256 node limit In-Reply-To: <11fa5cce050706103855a0470f@mail.gmail.com> References: <200507011649.j61GnMlY022352@oss.oracle.com> <20050701170449.GG26608@marowsky-bree.de> <42C5899E.2000209@oracle.com> <11fa5cce05070116517b7339b5@mail.gmail.com> <42CB1689.8040800@oracle.com> <11fa5cce050706103855a0470f@mail.gmail.com> Message-ID: <20050706180418.GA21089@ca-server1.us.oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com it would be entertaining to see how it even works... but uhm go ahead. would be a good test we sure don't have the hardware to do that On Wed, Jul 06, 2005 at 10:38:42AM -0700, Bruce Schwartz wrote: > Thanks. From looking at the code it appears that the maximum number of nodes > are controlled by some #defines (OCFS2_NODE_MAP_MAX_NODES, O2NM_MAX_NODES) > and that bumping the number up to something like 300 should be a simple > matter. There is a note in the code that reads: "if we need more, we can do > a kmalloc for the map" which I would guess addresses the case where you'd > want thousands of nodes. > > Is my reading correct? And would it be a bad idea to try to set up a 300+ > node OCFS2 system? > > Thanks, > Bruce > > On 7/5/05, Sunil Mushran wrote: > > > > It's actually 255. Yes, that doc needs to be updated. > > > > No, the algorithms did not play much role in setting this limit. > > Guess, can say the limit is part arbitrary, part practical. > > (That extra byte adds up pretty quickly.) > > > > Bruce Schwartz wrote: > > > > > Hi all -- > > > > > > In the "what's new in OCFS2" document at > > > > > http://oss.oracle.com/projects/ocfs2/dist/documentation/ocfs2-whats-new.txt > > > it says that the 256 node limit is a software limit and could be > > > lifted. Why is that limit there? Are there some algorithms that > > > don't scale nicely with larger number of nodes? I'm guessing that > > > there is more to it than saving a byte of RAM in a few data structures. > > > > > > Thanks, > > > Bruce > > > > > >------------------------------------------------------------------------ > > > > > >_______________________________________________ > > >Ocfs2-devel mailing list > > >Ocfs2-devel@oss.oracle.com > > >http://oss.oracle.com/mailman/listinfo/ocfs2-devel > > > > > > > > > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel@oss.oracle.com > http://oss.oracle.com/mailman/listinfo/ocfs2-devel