On Thu, 3 Feb 2011, Andreas Dilger wrote:

This patch adds the ability to skip zeroing the journal on disk.  This can
significantly speed up mke2fs with large journals.  At worst the uninitialized
journal is only a very short-term risk (if at all), because the journal will
be overwritten on any new filesystem as soon as any significant amount of data
is written to disk, unlike lazy_itable_init which can leave uninitialized
itable blocks indefinitely (in the absence of the kernel init thread).

Cheers, Andreas

Hi Andreas,

I think that we can skip the journal zeroing if the underlying device,
or the journal device supports discard, and advertise that discard
zeroes data. It is the same behavior as in the case of inode tables and
it would be nice to have the same thing for journal. Are you planning to
implement this as well ?

Thanks!
-Lukas