Backup Windows VM to single layer DVDs

I have posted this question on a Mac forum, but I got no reply. Because I don't want to keep installing my guest OSes each time I reformat my Mac, I have been trying to backup my Parallels VMs to DVD. I have successfully compressed my Linux VMs to fit on DVD, but I'm having troubles with Windows. Its "hdd" file, it was originall 10.76 GB but I was able to get it down to 8.91 GB (too big for both Dual layer and Single layer DVDs), with Parallels Compressor. Since converting sparsed images and compressing them into gzip files only lowers them to 5.44 GB (still too big for single layer, but more than small enough to fit on Dual layer DVDs), How can I compress it even further to make the Windows VM fit onto a single layer DVD? If I must, I will get an external hard drive or some double layer DVDs, but for now I want to save money and stick with my DVD-RW discs.

 

I back them up on an external hard drive. Much simpler, very fast to do, and less elbow grease needed.

 

True, I am aware of the advantages of an external hard drive over burning to DVD, but I want to put my Windows VM onto single layer DVDs since I don't have one and I prefer to save as much mney as I can; however, I am willing to buy the devices to get what I need done. Hopefully, I can get around to going to stores in the area so I can get an external hard drive. This would have been easier, if I still had double layer DVDs or gotten an external hard drive sooner.

 

XP SP2 is about 4.98GB in size, so its not possible to burn on a single layer DVD. I have used Roxio TOast and burn as 'spanned disk' (2 DVDs).

 

Use the already installed OS X command line tool, split, to split the hdd file into smaller parts. These can be written to DVD. To re-assemble them into the hdd you simply cat them:

# split winxp.hdd into roughly 2g splits named winxp-split.a??

split -b 2048m winxp.hdd winxp-split.a

#To recombine them use cat:
cat winxp-split.aaa winxp-split.aab winxp-split.aac >winxp.hdd

Burn the splits to a couple DVD's for safe keeping along with the rest of the contents of the winxp folder.

NOTE: The VM must be stopped, not suspended, and it's a good idea to turn off Parallels, too. See the man pages for split and cat. These Unix utilities have been around as long as Unix has been around and are safe, bullet-proof tools.

 

Thanks for the advice. I should probably print this thread, since all I was using were gzip, tar, and hdiutil. I'll reply back whether or not this works.

Update: Okay, I used the split command, but it first said, "illegal byte count", when I used 2g (since 2048 MB equals 2 gigabytes). Next, when I typed in "2048m" it said, "invalid argument". Maybe I should put the files in a disk image and split the gzip file. By the way, I read somewhere (don't really remember well), but I thought that I did not need those other files from the Windows XP folder, when backing up VMs, because the only files needed to be backed up were the "Windows XP.pvs" and "winxp.hdd" files.

Update 2: Okay, I found my problem, apparently, 2 gigabytes split are too big according to the split command, so I split the "hdd" file into parts with the size of 900 MB each. Thanks for the help.