file-max & file-nr:
-The kernel allocates file handles dynamically, but as yet it
-doesn't free them again.
-
The value in file-max denotes the maximum number of file-
handles that the Linux kernel will allocate. When you get lots
of error messages about running out of file handles, you might
want to increase this limit.
-Historically, the three values in file-nr denoted the number of
-allocated file handles, the number of allocated but unused file
-handles, and the maximum number of file handles. Linux 2.6 always
-reports 0 as the number of free file handles -- this is not an
-error, it just means that the number of allocated file handles
-exactly matches the number of used file handles.
+Historically,the kernel was able to allocate file handles
+dynamically, but not to free them again. The three values in
+file-nr denote the number of allocated file handles, the number
+of allocated but unused file handles, and the maximum number of
+file handles. Linux 2.6 always reports 0 as the number of free
+file handles -- this is not an error, it just means that the
+number of allocated file handles exactly matches the number of
+used file handles.
Attempts to allocate more file descriptors than file-max are
reported with printk, look for "VFS: file-max limit <number>