Re: Can I *not* have an on-disk cache?

On Jul 13, 6:57pm, Henrik Nordstrom (possibly) wrote:
> Steve Willer wrote:
>
> > What do you mean by "soft updates"?
>
> Make the filesystem behave like Linux has behaved all the time. Don't do
> strict updates of the on-disk filesystem when creating/deleting files,
> but buffer the changes in the filesystem cache to be flushed out at a
> later time by the kernel (where later is typically shortly).

If we're discussing FreeBSD "soft updates", well, no... soft updates
involves a lot more than that - namely rescheduling disk actions so
that nothing that isn't atomic will cause problems if it's
interrupted. One problem that the current soft updates implementation
(from Kirk McKusick, one of the authors of BSD) suffers from is a
tendency to wait on deleting files, and thus sometimes run out of disk
space, so I'm not sure if I'd advise doing this for squid. "async" is
another matter entirely.

> noatime is strongly recommended for any Squid cache disk. It takes away
> a lot of I/O burden from cache hits and directory accesses.

That's entirely different from soft updates.

        -Allen

-- 
Allen Smith				easmith@beatrice.rutgers.edu