Effects of Missing ext3 Parameters

[John]

Hi,

I have two 3TB (hardware RAID-5) ext3 filesystems and recently added
1TB to each. I resized each filesystem and e2fsck -f reports that both
are fine. However, when I look at the ext3 parameters with tune2fs -l
one seems to have some parameters that the other one doesn't. In
particular, one has: "Reserved GDT blocks", "Filesystem created",
"Default directory hash" and "Directory Hash Seed" while the other one
doesn't.

Doing some Googling, I found out that "Reserved GDT blocks" is only
important for online resizing. Since I don't do that, that's not an
issue for me. I figure that "Filesystem created" is just a timestamp
and is purely informational, so I think that's harmless if it's
missing.

But what about "Default directory hash" and "Directory Hash Seed"?
What are the effects of either/both of those parameters missing? How
can I set/change any/all of the missing parameters?

Thanks for any help you can provide.

John