From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020408 Description of problem: loopback devices above /dev/loop7 do not seem to be valid Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. put redhat iso images in /iso 2. mkdir /mnt/rh73-1 3. type command: [root@redhat mnt]# mount /iso/valhalla-i386-disc1.iso /mnt/rh73-3 -o loop=/dev/loop8 /dev/loop8: No such device [root@redhat mnt]# mount /iso/valhalla-i386-disc1.iso /mnt/rh73-3 -o loop=/dev/loop9 /dev/loop9: No such device [root@redhat mnt]# mount /iso/valhalla-i386-disc1.iso /mnt/rh73-3 -o loop=/dev/loop7 (works) Additionally, using the losetup command directly causes the same issues. losetup /dev/loop8 /iso/valhalla-i386-disc1.iso doesn't work, while the same losetup command on /dev/loop7 works just fine. Actual Results: loop7 works fine loop0 through loop7 work fine anything above loop7 does not work, with an error message of: No such device. Expected Results: I expected the loopback devices to mount. I have included the output of strace at the URL above. Additional info: a look in the /dev/loop* directory with extra information, shows that the mknods were performed correctly, so it's not like somebody forgot to include some block files in the distro: [root@redhat mnt]# ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 Apr 11 10:25 /dev/loop0 brw-rw---- 1 root disk 7, 1 Apr 11 10:25 /dev/loop1 brw-rw---- 1 root disk 7, 10 Apr 11 10:25 /dev/loop10 brw-rw---- 1 root disk 7, 11 Apr 11 10:25 /dev/loop11 brw-rw---- 1 root disk 7, 12 Apr 11 10:25 /dev/loop12 brw-rw---- 1 root disk 7, 13 Apr 11 10:25 /dev/loop13 brw-rw---- 1 root disk 7, 14 Apr 11 10:25 /dev/loop14 brw-rw---- 1 root disk 7, 15 Apr 11 10:25 /dev/loop15 brw-rw---- 1 root disk 7, 2 Apr 11 10:25 /dev/loop2 brw-rw---- 1 root disk 7, 3 Apr 11 10:25 /dev/loop3 brw-rw---- 1 root disk 7, 4 Apr 11 10:25 /dev/loop4 brw-rw---- 1 root disk 7, 5 Apr 11 10:25 /dev/loop5 brw-rw---- 1 root disk 7, 6 Apr 11 10:25 /dev/loop6 brw-rw---- 1 root disk 7, 7 Apr 11 10:25 /dev/loop7 brw-rw---- 1 root disk 7, 8 Apr 11 10:25 /dev/loop8 brw-rw---- 1 root disk 7, 9 Apr 11 10:25 /dev/loop9 lsmod shows the loopback module installed and running. I'm not including the output of that, because it's not particularly interesting.
Doh. The mkdir command, in steps reproducible should be: mkdir /mnt/rh73-1 not mkdir /mnt/rh73-3
You need to set the maximum number of loop devices - the default is 8. Since you're using it as a module, echo "options loop max_loop=16" >> /etc/modules.conf should fix it. Most people never need 8 loopbacks, and leaving the default low saves memory, hence the need for you to change your configuration.