On Oct 15, 2009, at 9:55 AM, Matthew Ingersoll wrote: > > On Oct 15, 2009, at 8:19 AM, Ed Cashin wrote: >> What am I saying? The main problem is the page cache. The I/O for >> the components of the RAID 0 will go through the page cache on each >> of >> the two AoE initiators, and without some way for the two hosts to >> make >> sure that the page cache contents match (e.g., "I just changed the >> data here---update your cache!") the scenario won't work. > > At what layer(s) does page cache come into play? I know the gist of > how it functions but not the dirty details. I thought it only came > into play when using a filesystem? > For example, if the controllers shared a block device using vbladed, > running with direct io wouldn't ensure consistency on both > controllers? >
And what about the buffer cache? Does direct/O_DIRECT mode bypass this also? From the setup I described there are no filesystems and page cache wouldn't play a role but buffer cache would (right?). -- Matth ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Aoetools-discuss mailing list Aoetools-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/aoetools-discuss
