Subject: Re: Soft update code integrated into the main tree
To: Todd Cohen <email@example.com>
From: Frank van der Linden <firstname.lastname@example.org>
Date: 11/15/1999 23:23:08
On Mon, Nov 15, 1999 at 04:40:00PM -0500, Todd Cohen wrote:
> Ok, I've seen this mentioned many times, and I just can't figure out what
> soft update is.. can someone please enlighten me? :)
What it basically comes down to is that metadata (i.e. inode, directory,
etc) writes to FFS filesystems are not done synchronously anymore.
Instead, they are delayed, while their order is kept intact by
keeping a list of dependencies. This leaves you with a consistent image
on disk should things crash. If metadata writes were delayed without
ensuring their order, this could lead to severely damaged filesystems.