Thus spake Erik Justus Paiewonsky <[EMAIL PROTECTED]>: > There has been a lot of to and fro about de-fragging. I submit that a > seriously fragmented HD or Volume, (YMMV), will probably lead to some > data, at some point in time, overwriting other data.[...] I am not a > Panther user yet, but since it too is a Unix-based System SW, the > potential for files being overwritten on fragmented bits of > data will persist, even if Panther does a better number on this than > does Jaguar.
Erik is right, but only on a disk that is SERIOUSLY fragmented, which is quite rare on a modern machine, despite what Norton would have you believe. I have seen NDD report that a disk was "seriously" fragmented at only a couple of percent. Even a few TIMES that amount of fragmentation will not have a discernible effect on OS performance given the nature of the Mac, the HFS disk format, and the speed, buffering, caching, and read ahead capabilities of modern disks. (Note: video editors would be well advised to keep all working data on an otherwise unused disk.) I have NEVER lost data to fragmentation, but the last time I defragmented a drive, it wouldn't boot. I simply don't trust Speed Disk, and in fact would never use any third party utility like NDD or TechTool on a properly working drive Apple KB Article ID 17933 states: "The file system used on Macintosh computers is designed to work with a certain degree of fragmentation. This is normal and does not significantly affect performance for the majority of users. You should not need to frequently defragment the computer's hard disk." And another TidBITS article states that "optimizing disks is a waste of time. <http://db.tidbits.com/getbits.acgi?tbart=07254> Longer excerpt: "So where did this cult of disk optimization come from? Back in the early days of Windows, and DOS before that, PCs used the FAT (File Allocation Table) file system. Legend has it that the FAT file system was pretty bad about fragmenting files, so disks quickly became badly fragmented. Back then, disks - and computers in general - were extremely slow, especially by today's standards. With those painfully slow disks and computers, optimizing a disk could provide noticeable performance improvements. Modern computers and disks are of course much faster, and they also have much larger and more sophisticated disk caches, all of which significantly reduces the impact of a fragmented disk. When Apple designed the HFS (Hierarchical File System) file system for the Mac, and later when they replaced HFS with HFS+, they took special care to try to minimize fragmentation. All hard disks store data in 512 byte chunks called sectors. FAT, HFS, and HFS+ use larger chunks, called clusters on FAT and allocation blocks on HFS. One purpose of clusters and allocation blocks is to try to reduce fragmentation, by storing files in larger pieces. But HFS goes one step further. When saving a file to disk, the Mac file system allocates space in even larger chunks, called clumps, in a further effort to reduce fragmentation. [...] HFS will never fragment a file if it can be avoided." -- To unsubscribe: <mailto:[EMAIL PROTECTED]> archives: <http://www.mail-archive.com/entourage-talk%40lists.letterrip.com/> old-archive: <http://www.mail-archive.com/entourage-talk%40lists.boingo.com/>
