How to get ISOs for iODD

[timeshifter]

You can also do this

Create a bootable installer for macOS - Apple Support

Use an external drive or secondary volume as a startup disk from which to install macOS.

support.apple.com

Yes you can. But you need a separate USB drive or a drive with lots of partitions, one for each OS. The method I'm posting about creates an ISO file. I don't burn the ISO to a disc. I use the ISO in my iODD device.

https://www.amazon.com/gp/product/B00S3G12E6

I can have up to 32 ISO files that I can select from a menu on the device. Beats the heck out of carrying around multiple USB drives.

 

[timeshifter]

How to for macOS Monterey:

Create ISO file for Mac OS system (Monterey) | WIKI CODE

The below commands will help you create the iso file this command will download the newest version. - softwareupdate --fetch-full-installer 1- to install MacOS Monterey use the below command - softwareupdate --fetch-full-installer --full-installer-version 12.0.1 2- we must create a temporary...

www.wikicoode.com

I had already downloaded my installer from the App Store so I didn't run step 1, just went straight to step 2. Note that I modified the volume size to 14000 instead of 12500 as that was too small for the current version.

 

[Aquenon]

I hate to reply to a thread that's been inactive since February, but it's the perfect fit for my question and probably better than starting a new thread.

I have an iODD ST400. I've used the guide to create the ISO and it is selected. When plugging into a computer, the correct ISO (El Capitan) automatically shows in Finder as a DVD. But when trying to boot, Startup Manager does not show the El Capitan installer and shows nothing at all from the iODD. Granted, this is a 2008 Mac Pro. Is there a limit to how far back the iODD's work for Macs?

Also, are you using an ISO or a VHD on your iODD. From reading this, I'm sure it's the ISO, but just wanted to make sure.

 

[timeshifter]

Is there a limit to how far back the iODD's work for Macs?

Also, are you using an ISO or a VHD on your iODD.

I am not aware of a limit on the age of the Mac.

Definitely using ISO and not VHD.

 

[Markverhyden]

I hate to reply to a thread that's been inactive since February, but it's the perfect fit for my question and probably better than starting a new thread.

I have an iODD ST400. I've used the guide to create the ISO and it is selected. When plugging into a computer, the correct ISO (El Capitan) automatically shows in Finder as a DVD. But when trying to boot, Startup Manager does not show the El Capitan installer and shows nothing at all from the iODD. Granted, this is a 2008 Mac Pro. Is there a limit to how far back the iODD's work for Macs?

Also, are you using an ISO or a VHD on your iODD. From reading this, I'm sure it's the ISO, but just wanted to make sure.

Was it running before this activity?
If so what version OS?
What procedure did you actually use to build the ISO?
How is the IODD drive setup?
It's been ages since I worked with IODD but do remember it being finicky with macOS. I'd probably try building a regular bootable USB stick.

 

[Aquenon]

Thanks for the replies!

1. Yes
2. It's currently running Catalina using Dosdude1's patch. But it's buggy, so I'm trying to get the last supported version put back on it. It's a server now, so I don't need the latest OS anyway. I just need it stable, and Catalina is not stable on a 2008, at least not mine. Plus, I'm taking to time to learn the iODD.
3. The script for El Capitan posted on this thread.
4. Two partitions, 1 exFAT for the ISOs, and 1 NTFS for any VHD's I may want to put on there later.

I think I found the issue. The script makes a DVD ISO. That turns out to be a problem with older Macs that already have an internal optical drive which this one does, well did. It's still there but non-functional. External optical drives are only bootable "with Mac models from 2008 and later that don't have a built-in optical drive." So because the ISO shows as a DVD, it won't load in the Startup Manager so I can boot from it. I'll have to find a method that makes an ISO that doesn't show as an optical drive.

I've tried making an image in Disk Utility and using Apple's command (https://support.apple.com/en-us/101578) to make a disk. That works, but I'm not finding the right commands to convert that DMG to an ISO. I might go to my storage unit this week and try to find my old thumbdrives and make a bootable drive from that and than try to image an ISO from that. The server isn't critical. It's useable, it just reboots several times per day. Annoying, but I can deal with it until I figure out how to make the right ISO for the iODD that also works with this old Mac.

 

[Markverhyden]

Personally I'd just use diskmakerx to build the USB stick. I've had problems with those KB's on occasion building installers. How old are the installer image(s). Some years ago Apple had an expired root cert which caused the installers to fail if using the current date and time. You could either roll the date back or download a current installer. Personally I'd try installing 10.7 or .8 before going to 10.10

 

[HCHTech]

The server isn't critical. It's useable, it just reboots several times per day. Annoying, but I can deal with it until I figure out how to make the right ISO for the iODD that also works with this old Mac.

Are you sure the "reboots several times per day" symptom isn't a hardware issue? On a 15-year-old machine, anything is possible. Overheating, for example...

 

[britechguy]

Overheating, for example...

True, and sometimes the level of dust bunnies inside 15-year-old equipment is simply not to be believed and getting those out of there can make a difference.

 

[Aquenon]

It’s worth checking out, definitely. I clean it out regularly, but it is in a new spot than where it was last time, so there could be more dust in this part of the house. I’ll check when I get off of work.

I did find an article that was specifically about allowing Mac’s with internal optical drives to boot from a USB external optical drive (which is what it sees the ISO as). I’ll report back if that works in case anyone in the future has this same problem. The iODD is listing the image with defrag every time I try to select it. Going to look and see if there’s a way to defrag an ISO on macOS or Linux. iODD’s documentation only lists Windows tools. I have lots of stuff to test this weekend.