From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Schwartz Date: Wed Jul 6 12:38:36 2005 Subject: [Ocfs2-devel] 256 node limit In-Reply-To: <42CB1689.8040800@oracle.com> References: <200507011649.j61GnMlY022352@oss.oracle.com> <20050701170449.GG26608@marowsky-bree.de> <42C5899E.2000209@oracle.com> <11fa5cce05070116517b7339b5@mail.gmail.com> <42CB1689.8040800@oracle.com> Message-ID: <11fa5cce050706103855a0470f@mail.gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com 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 > > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://oss.oracle.com/pipermail/ocfs2-devel/attachments/20050706/fa6dc4e6/attachment.html