mounting with loop devices.

[E Frank Ball]

On my Linux server at work I'm mounting iso images as filesystems to
save disc space.  I have /etc/fstab entries like this:

/home/ftp/pub/RedHat/psyche-i386-disc1.iso      
	/home/ftp/pub/RedHat/psyche-i386-disc1 iso9660 loop,ro 0 0

As I was trying to setup the RedHat 8.0 isos I discovered that using
more that 16 /dev/loop devices doesn't seem to work.

RedHat supplied 8 /dev/loops, but I made 8 more with:
mknod --mode=660 loop9 b 7 9
mknod --mode=660 loop10 b 7 10
etc.

But beyond number 15 they don't work.

penguin:/dev 287% ll loop*
brw-rw----    1 root     disk       7,   0 May  5  1998 loop0
brw-rw----    1 root     disk       7,   1 May  5  1998 loop1
brw-rw----    1 root     disk       7,  10 Nov 29  2001 loop10
brw-rw----    1 root     disk       7,  11 Nov 29  2001 loop11
brw-rw----    1 root     disk       7,  12 Nov 29  2001 loop12
brw-rw----    1 root     disk       7,  13 Nov 29  2001 loop13
brw-rw----    1 root     disk       7,  14 Nov 29  2001 loop14
brw-rw----    1 root     disk       7,  15 Nov 29  2001 loop15
brw-rw----    1 root     disk       7,  16 Oct  3 14:40 loop16
brw-rw----    1 root     disk       7,  17 Oct  3 14:40 loop17
brw-rw----    1 root     disk       7,   2 May  5  1998 loop2
brw-rw----    1 root     disk       7,   3 May  5  1998 loop3
brw-rw----    1 root     disk       7,   4 May  5  1998 loop4
brw-rw----    1 root     disk       7,   5 May  5  1998 loop5
brw-rw----    1 root     disk       7,   6 May  5  1998 loop6
brw-rw----    1 root     disk       7,   7 May  5  1998 loop7
brw-rw----    1 root     disk       7,   8 Nov 29  2001 loop8
brw-rw----    1 root     disk       7,   9 Nov 29  2001 loop9

Anybody know how I can make more /dev/loop files work?  I'm using kernel
2.2, would 2.4 be any better?  Is there some kernel parameter that can
be tweeked?  (I looked around a little but couldn't find anything, but
I'm no kernel hacker).

-- 

   E Frank Ball             /dev/loop at efball.com