On Tue, Mar 31, 2009 at 04:04:53PM +0100, Chris Rees wrote: > On Tue, 31 Mar 2009 16:00:18 +0530 > manish jain <invalid.poin...@gmail.com> wrote: > > Having bgfsck enabled is like > > inviting a dragon to dinner when this happens. > > 2009/3/31 RW <rwmailli...@googlemail.com>: > > If you've done a normal install, soft-updates aren't enabled on /, > > so it will get foreground checked by default. > > > > If I were you I'd reboot into single user mode and do a full fsck on it. > > > Seriously, why is everyone against background fsck? Can anyone give a > good reason? Please?
For background fsck to work as it is supposed to, it is necessary that only certain errors can occur on the filesystem. Other types of errors cannot be corrected by a background fsck. To make sure that only the allowable errors can occur it is necessary for soft updates to be used and working as it is supposed to. For soft updates to work as it is supposed to the disk subsystem must provide certain guarantees on when and in which order blocks are written. Normal PATA/SATA disks with write caching enabled (which is the default) do not provide these guarantees. Disabling write caching on will make them adhere to the assumptions that soft updates make, but at the cost of a severe performance penalty when writing to the disks. In short therefore on a 'typical' PC you can fairly easily get errors on a filesystem which background fsck cannot handle. It is also the case that background fsck relies on snapshots to work, At least in the past snapshots had stability problems. Things are supposed to be better these days, but many people have long memories for these kind of problems. -- <Insert your favourite quote here.> Erik Trulsson ertr1...@student.uu.se _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"