On Fri, Mar 19, 2004 at 11:15:46PM -0600, Lincoln Dunn wrote: > this is incorrect, as it applies to OS X. Journaling actually > only writes all changes to metadata to a log file to maintain your > filesystem consistency
Which means that AppleWorks (the original, Apple II implementation) has more sophisticated "journaling" than Mac OS X: it did the data too. (Technically, it wasn't journaling. It simply saved the document as a scratch file then saved the document over the original file, so you would always have a document in a known state). > on any more modern Mac, is a very, very slight performance hit. If there is any performance hit. It seems as though most versions of Unix (including Mac OS X) place a very low priority on file I/O. You would have to have a pretty heavy load on your CPU before user processes and disk I/O would be competing for CPU cycles. > you're right in that there is a type of journaling that writes both > the metadata and the data to the drive, but it's really rare, since > you can achieve the same thing with a RAID The metadata and data bit is common in the Linux world, but journaling was a recent addition and it probably reflects the reality of modern hardware: we have more CPU cycles than we know what to do with. I'm not sure that RAID accomplishes the same thing. The data recovery bits of RAID seem to be concerned with the failure of the storage media, while journaling seems to be concerned with maintaining the consistency of the file system (may it be metadata or data oriented). For the former you may loose your file system, while you may loose your file in the latter. Byron. -- Mac Canada is sponsored by <http://lowendmac.com/> and... Shop Canadian, visit Mantek Services <http://www.mantek.mb.ca> Low Prices That Will Keep YOU and Your MAC Smiling Educational discounts are now available Support Low End Mac <http://lowendmac.com/lists/support.html> Mac Canada info: <http://lowendmac.com/lists/mac-can.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/mac-canada%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
