VMWare ESX fails to mount ISO image

I was installing the newest OpenSolaris on VMware ESX 3.5 tonight and I wanted to mounted to verify my disk image prior to the install so I thought simple; mount the ISO and browse the file system and that will show everything is ok. I created the mount point and ran the Linux mount commands and got an IOCTL error.

[root@x4100 x4100:storage1]# mkdir /tmp/isoimage
[root@x4100 x4100:storage1]# mount -o loop /vmfs/volumes/x4100\:storage1/OpenSolaris.iso /tmp/isoimage/


ioctl: LOOP_SET_FD: Invalid argument
 
After a lot of research I found this article. That explains that if you try to mount an ISO image from a VMFS file system you get the aforementioned error. The problem I had is the ISO I was trying to mount is on a VMFS filesystem and the mount command only works for images residing on a Linux filesystem, and vmfs doesn't count as a Linux filesystem. 

I moved the ISO to the /tmp filesystem and everthing worked as expected.

[root@x4100 x4100:storage1]# mv OpenSolaris.iso /tmp
[root@x4100 x4100:storage1]# mount -t iso9660 -o loop /tmp/OpenSolaris.iso /tmp/isoimage
root@x4100 x4100:storage1]# cd /tmp/isoimage/

[root@x4100 isoimage]# ls
bin dev jack pkg.zlib proc root solarismisc.zlib system
boot devices mnt platform reconfigure save solaris.zlib tmp
[root@x4100 isoimage]# cd ..
[root@x4100 tmp]# umount /tmp/isoimage/