previous - next - up - title - contents - index

5.47 Disk images on hard disk

Device type: image

Windows NT UNIX
device=image device=image
drive=D:\fakedisk.iso drive=/fakedisk.iso

Instead of real CD drives you can also use ISO 9660 formatted hard disk images of CDs (see also "iso9660" on page 139). If the file D:\fakedisk.iso or /fakedisk.iso is an ISO 9660 formatted disk image, it can be accessed with the above device description file. The file system of the image appears as a subdirectory in the file system of iXOS-JUKEMAN, as if it was a real CD in a real drive. Using this method you can set up small and fast CD servers running on hard disks only. For example with 20 CDs containing 200 MB each, you can set up a server by copying the CDs on a 4 GB hard disk and adding lines in the format

drive=<image>

below

device=image

in the device description file.
A convenient way to copy CDs to hard disk is the program cdglow.

Example:
cdglow -s \\.\p0b0t4 -t D:\images\fakedisk.iso -T

or

cdglow -s /dev/iXOS_SCSI0/4 -t /images/fakedisk.iso -T

This will copy the CD in the drive with SCSI ID 4 on the first SCSI bus to the specified file.
On Windows NT even more CDs can be copied to hard disk if you use the transparent compression feature of NT. Mit NTFS you can compress a file or a whole directory tree transparently. To do this, create a directory such as \images on an NTFS partition, and compress it with the file manager. All images created in this directory will be compressed automatically.
Another way to create ISO 9660 files is to use the formatting program iso9660. See "iso9660" on page 139.
Thus, hard disk images and transparent compression can be used to set up cost-effective and fast CD servers. Used in combination with jukeboxes the overall performance can be increased if the most frequently accessed disks are replicated as hard disk images.


previous - next - up - title - contents - index