Hi, Andrew!

> > The original journalling worked like this:
>
> May I ask a question?
>
> Does the current breed of journalling filesystems (eg. on Linux, ext3,
> Reiser, jfs) provide any DB protection? Is it worth using them, or

just

> unecessary overhead?

Journalling allows recovering database to an arbitrary point of time (in
Oracle, Informix, and probably others).

But in fact, if you set up database on a volume that supports recovery
to a point of time you get the same benefits, but at hardware speed.
AFAIK, SAN devices commonly support this feature. Some of them use
journaling; some use "write anywhere" technology (means each time you
write something it is written to a new location, old data is preserved
for recovery purposes).

Those high-end features slowly migrate into Linux kernel. Clustered
filesystems, logical volume manager and software RAID are already there.

BTW, hint: software RAID mirroring is much faster than Firebird
shadowing and is more reliable. You can set it up on a network block
device if you are so inclined. :)

> Andrew Gough

Nickolay