Cannot create gjournal on gmirror partition - 8.2-RELEASE: "No such file or directory"

[perryh at pluto.rain.com]

Hugo Silva <hugo at barafranca.com> wrote:

> gm0s1h is a 1.4T partition ...
>
> While attempting to create a gjournal there:
> # gjournal label /dev/mirror/gm0s1h
> gjournal: Cannot clear metadata on /dev/mirror/gm0s1h: No such file or 
> directory.

One problem is that "gjournal label /dev/mirror/gm0s1h" (specifying
only one provider) asks gjournal to create the journal on the same
provider which holds the data.  That only works if the provider
is empty.  (However I don't know whether that is the cause of the
particular message you're getting.)

> Another thing: We've noticed that system becomes very unresponsive
> x.. while bgfsck is running on that big partition. However, the
> same doesn't happen while gmirror is syncing, at 80MB/s. Does
> anyone know why one operation (fsck on huge partition) impacts the
> systems performance so much, while another (gmirror sync) does not?

I would hazard a guess that your system is memory constrained, and
that fsck's working set -- especially when running on a very large
partition -- is considerably larger than what's needed to perform
a simple data-copy operation to sync a mirror.  Adding more memory
might help.