AIX Tip of the Week

Subject: Mounting an ISO File in AIX and Linux

Audience: All

Date: June 20, 2006

This tip covers how to mount an "iso" file as a filesystem in AIX and Linux. An "iso" file is a CD-ROM image, and is typically used to "burn CD's". If you don't have a CD burner, you can use this technique to access the files in the "iso" file.


In AIX you "dd" the "iso" file into a raw LV, then mount the LV as a filesystem Here's are the steps for copying the iso named image.iso into "/cd1iso", a JFS filesystem

  1. Create a filesystem with size slightly bigger than the size of the iso image. Do NOT mount the filesystem.
    # /usr/sbin/crfs -v jfs -g rootvg Megabytes -a size=800 -m/cd1iso -Ano -pro -tno -a frag=4096 -a nbpi=4096 -a ag=8

  2. Get the logical volume name associated with the new filesystem:
    # lsfs | grep cdiso (assume it's /dev/lv00)

  3. dd the "iso" image into rlv00 (raw lv00):
    # dd if=image.iso of=/dev/rlv00 bs=10M

  4. Alter /cdiso stanza in /etc/filesystems => vfs=cdrfs and options=ro (read-only)
            dev             = /dev/cd1_lv
            vfs             = cdrfs
            log             = /dev/loglv00
            mount           = false
            options         = ro
            account         = false

    Update 6/21/06: Command line alternative: chfs -a vfs=cdrom cd1iso

  5. Mount the file system :
    # mount /cd1iso


You can directly mount an "iso" file in Linux using the following command:

# mount -o loop -t iso9660 image.iso /cd1iso

Bruce Spencer,

June 20, 2006