Subject: Re: mount -o softdep, fsck, and tunefs
To: Peter Seebach <email@example.com>
From: Oleg Polyanski <Oleg.Polianski@clear.co.nz>
Date: 11/15/2001 13:50:46
firstname.lastname@example.org (Peter Seebach) writes:
> Originally, softdeps were a tunefs option, because fsck needed to know
> which way to handle the filesystem; I understand there are some differences
> between FFS with softdeps and FFS without. Now that it's a mount option
> instead, how does fsck guess whether a filesystem was using softdeps when
> last mounted?
If I'm not mistaken, soft dependencies do not require any meta data layout
changes, it's only the way how the file system data is handled inside FFS
code in the kernel. The changes will only appear when the FFS snapshots are
introduced. There was an article about FFS, soft dependencies and snapshots
in USENIX 2000 materials written by Kirk McKusick.