Michael Mansour said...

|I'm really after knowledge to know if inodes can be given to a filesy=
|stem while the filesystem is online and mounted.

As the man page you quoted said:

|Be warned that is not possible to expand the
|number of inodes on a filesystem after it is
|created, so be careful deciding the correct
|value for this parameter.

It's better to waste some space with inodes you'll
never use than to run out.  I won't swear there's
not a way around this, but the only remedy I've
ever heard of was save, mkfs, and restore as you
mentioned.  I've had to do it, but only a couple
of times.  It's been a long time since it bit me
on a stock mount point, but for tier 2 storage
filesystems I usually allocate some extra inodes
when I use ext2/3.

Otherwise, you'll have to consider different types
of filesystems.  xfs, for instance, can grow the
number of inodes dynamically, even to consume the
entire fs if you set it up that way.

-Miles