inode-max and file-max question

[Ben Yau]

Hi there Linux and kernel gurus...


I was curious about a few things.

1) What is the theoretical and practical max for file-max and inode-max?
I'm assuming it is related to either disk capacity or RAM.  Also, did
inode-max go away at a certain kernel revision?   A user wants to set
something up with reporting that will eventually generate around 15million
files or so.  One google/usenet article i found related it to physical
memory.  If RAM is N

N/4*256 = file-max
file-max*4 = inode-max

Both seem a bit short to me for theoretical max.  (not the
file-max*4=inode-max part but the N/4*256=file-max part)

2) is there a reason inode-max doesn't exist anymore?

3) How do the below numbers relate for file-max (and indirectly inode-max I
guess) and the output for df -i ?

[byau at testmachine fs]$ more /proc/sys/fs/file-max
::::::::::::::
/proc/sys/fs/file-max
::::::::::::::
8192
[byau at testmachine fs]$ df -i
Filesystem            Inodes   IUsed   IFree IUse% Mounted on
/dev/sda2              64512    9450   55062   15% /
/dev/sda1                512      35     477    7% /boot
/dev/sda3             256512   81440  175072   32% /usr
/dev/sda5              64512     859   63653    1% /var
/dev/sda7              26208      12   26196    0% /tmp
/dev/sda8             257280   50650  206630   20% /home
[byau at testmachine fs]$


Thanks!!
Ben Yau