Op maandag 08-10-2007 om 13:16 uur [tijdzone -0400], schreef Phillip Susi: > Jan Claeys wrote: > > But I think a similar API could be used to mark & move bad sectors or > > "lost" sectors, and that's more related to this discussion... > > As I said, there is no need to make such an effort because ext rarely > becomes fragmented enough to worry about. The fact that the defrag > package has not really been maintained in 10 years shows that there is > no strong need for an offline defrag, let alone an online one.
The main reason (IMO) why "defrag" is not useful (anymore) is that for ages there hasn't been any (guaranteed) correlation between hardware order and software order of sectors on a disk. Defragmenting disks might actually fragment them more on a fysical level, and thus cause slow-downs. And in some cases (fysically) fragmented sectors might be faster to read/write than non-fragmented ones (I used a custom, partially self-written, diskette formatting program to do exactly that under MS-DOS!). So, any defrag program would require help from the hard disk's firmware to be really efficient (and AFAIK no firmware supports this). But, what I was thinking about was similar atomic operations that allow _other_ filesystem cleaning tasks to be done while a filesystem is in use (r/w). ('fsck' might be an example.) I understand these don't exist now, but they might be a good idea for future filesystems or filesystem versions... :) -- Jan Claeys -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss