INT 21 - Novell NetWare - FILE SERVER - GET FILE SYSTEM STATISTICS
        AH = E3h subfn D4h
        DS:SI -> request buffer (see below)
        ES:DI -> reply buffer (see below)
Return: AL = status
            00h successful
            C6h no console rights
Notes:  this function is supported by Advanced NetWare 2.1+
        the calling workstation must have console operator privileges
SeeAlso: AH=E3h/SF=C8h,AH=E3h/SF=D9h,AH=E3h/SF=E7h,AH=E3h/SF=E8h

Format of request buffer:
Offset  Size    Description
 00h    WORD    0001h (length of following data)
 02h    BYTE    D4h (subfunction "Get File System Statistics")

Format of reply buffer:
Offset  Size    Description
 00h    WORD    (call) 0028h (size of following results buffer)
 02h    DWORD   clock ticks since system started
 06h    WORD    maximum open files set by configuration
 08h    WORD    maximum files open concurrently
 0Ah    WORD    current number of open files
 0Ch    DWORD   total files opened
 10h    DWORD   total file read requests
 14h    DWORD   total file write requests
 18h    WORD    current changed FATs
 1Ah    WORD    total changed FATs
 1Ch    WORD    number of FAT write errors
 1Eh    WORD    number of fatal FAT write errors
 20h    WORD    number of FAT scan errors
 22h    WORD    maximum concurrently-indexed files
 24h    WORD    current number of indexed files
 26h    WORD    number of attached indexed files
 28h    WORD    number of indexed files available
Note:   all fields except the first are big-endian