Disassembling a large file, moving it, and reassembling it on another machine

July 9, 2009 12:06 PM

I have a large .iso file to transport. If I split the file and burn it onto two DVDs, can I combine them again once they're on the target machine? How?

I have a large (8.55 GB) .iso of program files which I'd like to burn for transport and installation onto another computer. I gather this requires splitting the file into two parts so it will fit onto two DVDs. I'm in the process of splitting and burning it now (using winrar), but I am not sure what to do with the data to make it installable once I get it onto the target machine. Is there a way to recombine the two parts into the original huge .iso file? If so, I could probably mount it with daemon tools or something and install it this way... Any help or suggestions would be appreciated!

[side note: I am asking this question on behalf of a friend. Not that I'd be embarrassed to ask the same question myself!]

posted by not_on_display to computers & internet (10 comments total)

If you're using WinRAR, you don't need to do anything special. Once the two files are transferred onto the new machine, unzipping it again with WinRAR (and with both parts in the same folder) will give you a copy of the original .iso file in one part. Then you just mount it using Daemon Tools or Power ISO, and you're good to go. I don't know what the specific question is?
posted by Phire at 12:08 PM on July 9

winRAR on the other end does this. If it doesn't mount on the other end then it's not mountable.
posted by jessamyn at 12:27 PM on July 9

If you can burn double layer DVD on your computer then it will probably save you some trouble. Double Layer DVD (DVD+R DL) holds about 8.55 GB worth of data.
posted by jstarlee at 12:43 PM on July 9 [1 favorite]

Likes like the image file may be just a smidge too big. The wikipedia article on DVD+R DL is rather informative. WinRAR may be the best bet for file segmentation and re-assembly. DVD+R DL holds just under 8.55 GB of data.
posted by PROD_TPSL at 1:07 PM on July 9

I'd burn the image directly to a dual layer disc. Files over 2 gig aren't always visible on a DVD - I know it's fine on Linux, but not on OSX.
posted by Pronoiac at 2:08 PM on July 9

I would never, ever use compression for this.

You want some sort of concat software. If you're on a Mac, I'd recommend Split and Concat; if you're on a PC, I'm sure someone else around here can help you out.

What this program will do is take a file—say, BIG.iso (8 GB)—and split it into two files: BIG.iso.001 (4 GB) and BIG.iso.002 (4 GB). There are settings, depending on the program, for how big each chunk is. Just burn each part onto its own DVD, copy the parts onto the destination computer, and presto.

The only catch is, you'll need a similar program on the destination computer as well. (A flash drive, or even one of the DVDs, should easily hold an application like that.)
posted by reductiondesign at 2:09 PM on July 9

Just noticed the install part, sorry. Once you've got the full intact .iso on the computer, either open it with Daemon Tools (PC) or something like Toast (Mac).
posted by reductiondesign at 2:11 PM on July 9

Thank you all for your helpful answers. My friend the asker figured out how to get her LAN to recognize the two computers, and they each other; presto!
posted by not_on_display at 3:18 PM on July 9

Original asker adds: "Thanks for the advice here. As not_on_display said, I was able to solve my immediate problem by transferring the iso in one lump via LAN, but I would still like to burn a disk backup, so this information is very useful to me.

"I'm curious as to why reductiondesign says not to use compression for this? Is it an issue of degradation? I'm on a PC, by the way."
posted by not_on_display at 12:49 PM on July 10

I was avoiding compression simply because that's a huge amount of data to compress and could take a while. No other reason, really.
posted by reductiondesign at 1:01 PM on July 10