On Tue, Jul 25, 2006 at 01:22:53PM +0200, Mark Perry wrote: > I believe that several DB systems offer direct/raw I/O to avoid Linux cache > problems, and that journaling filesystems, although by default only journal > meta-data, offer mount options to journal data too. This of course comes at > a performance price, though Hans Reiser did claim that the new Resier4 FS > will journal data without the previous performance penalties.
Journalled filesystems only journal buffered I/O. Direct I/O means you do direct dma operations from the storage controller to the user address space. It's physically impossible to journal. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
