Unix Tip: Burning bootable DVDs

One of the messages that you don't want to see when getting ready to upgrade a system to Solaris 10 is "can't open boot device". The problems this kind of error suggests, such as bad CD/DVD reader or improper device alias, can be troublesome. So, when I ran into this problem on a Friday afternoon, I was not amused. I had tried various boot commands, but got the same basic response each time:

{3} ok boot cdrom -s
Boot device: /pci@8,700000/scsi@1/disk@6,0:f  File and args: -s
Bad magic number in disk label
Can't open disk label package

Can't open boot device

I remembered that the DVD I was using was one that I had burned at the tail end of a frustrating weekend a few weeks earlier so I had to admit that it was suspect. So, after noting the "can't open boot device" error, I took the DVD and inserted it into the CD/DVD reader on my laptop to see what it looked like. When I did, I noticed immediately what was wrong. Instead of seeing the series of files and directories I was expecting, what I saw was a single ISO file:

$ dir D:
 Volume in drive D is Solaris10_0807
 Volume Serial Number is 4797-2303

 Directory of D:\

01/20/2008  07:53 PM     3,485,204,480 sol-10-u4-ga-sparc-dvd.iso
               1 File(s)  3,485,204,480 bytes
               0 Dir(s)               0 bytes free

Oops. Somehow I hadn't burned the DVD properly. I had written the ISO file to the DVD, but not burned an ISO image. As a result, the DVD contained only the ISO file and was not going to boot my system.

ISO files are complete CD (or DVD) images, similar to the files you would create if you were to dump the contents of a hard disk or partition to a single file. Any of a number of free and otherwise software tools can be used to burn these images onto CD or DVD media as long as you have the appropriate burner. ISO files are so named because their format is that of an ISO 9660 file system.

The solution for me was, of course, to burn a new DVD using the ISO image. Putting the DVD with the ISO image in my CD/DVD reader and a blank DVD in my DVD writer, I then browsed over to my D: drive, right-clicked on the iso file and selected "Burn using ImgBurn". Once the new DVD was ready, I checked its contents to make sure it looked right this time. On my laptop, it looked like this:

$ dir E:
 Volume in drive E is SOL_10_807_SPARC
 Volume Serial Number is 2C90-FE33

 Directory of E:\

06/12/2007  10:43 AM                93 .CDTOC
08/16/2007  04:11 PM    <DIR>    .INSTALL
08/16/2007  04:10 PM                 0 .INSTALL_CONFIG
06/12/2007  10:43 AM               472 .SLICEMAPFILE
06/12/2007  10:43 AM             6,128 COPYRIGHT
08/16/2007  03:38 PM               257 INSTALLER
06/12/2007  10:43 AM           459,760 JDS_THIRDPARTYLICENSEREADME
08/16/2007  04:10 PM    <DIR>     LICENSE
08/16/2007  04:11 PM    <DIR>     SOLARIS_10
06/12/2007  10:45 AM                21 _VOLUME.INF
08/16/2007  03:36 PM                23 _VOLUME_INF.2
08/16/2007  03:37 PM                23 _VOLUME_INF.3
08/16/2007  03:37 PM                23 _VOLUME_INF.4
08/16/2007  03:38 PM                23 _VOLUME_INF.5
              11 File(s)        466,823 bytes
               3 Dir(s)               0 bytes free

This DVD looked like what I had expected to see in the first place and I was able to install Solaris 10 long before it was time to leave work for the weekend.

With Solaris 10 images available for easy (though time-consuming) download, being ready to burn your own installation media might save you time and a little money. Just make sure that, if you choose this route, that you burn an ISO image and not a regular file. Look to your burning software to have an option to "burn an image" or "copy an ISO file".