[URGENT!!!] Need Mavericks back, but keeping Yosemite

[AppleFan22]

Hi everyone,
I really need to get Mavericks back; I'm going going away later today and we won't have Wi-Fi, but we will have a dongle to bring. The installation doesn't work on Yosemite, but should work on Mavericks. I've got all the files and everything backed up, and a partition ready on the HDD, but how can I get Mavericks on this partition, and keep Yosemite?
Or can I create a duplicate of Yosemite on the HDD in the separate partition, and then use Time Machine to take it back to Mavericks?

Thanks guys!!

(I really want to keep Yosemite too, as I won't have time to reinstall it later today)

 

[CaffeinatedNoms]

Assuming you have purchased a copy of Mavericks in the past, and that the partition you have created is large enough:

1) Name your new blank partition something obvious. Like Mavericks.

2) Download Mavericks from the App Store

3) Run the installer. Tell it to install to the partition you just named Mavericks.

4) Wait

5) Wait some more

6) You're done after three reboots.

Edit: should install in Mavericks? As in you're not sure? Because this is a whole hour (or more, depending on Internet speed) of rigmarole to go through for something you're unsure about. If you have a capable phone (most iOS, Android, and WP7/7.5/8 phones), why not just do internet tethering?

 

[AppleFan22]

Assuming you have purchased a copy of Mavericks in the past, and that the partition you have created is large enough:

1) Name your new blank partition something obvious. Like Mavericks.

2) Download Mavericks from the App Store

3) Run the installer. Tell it to install to the partition you just named Mavericks.

4) Wait

5) Wait some more

6) You're done after three reboots.

Edit: should install in Mavericks? As in you're not sure? Because this is a whole hour (or more, depending on Internet speed) of rigmarole to go through for something you're unsure about. If you have a capable phone (most iOS, Android, and WP7/7.5/8 phones), why not just do internet tethering?

OH MY GOD IF THIS WORKS I WILL BE SO HAPPY! Thank you so much!! (I've tried installing other things in Yosemite, and they haven't worked either [Steam and Origin])

 

[AppleFan22]

Assuming you have purchased a copy of Mavericks in the past, and that the partition you have created is large enough:

1) Name your new blank partition something obvious. Like Mavericks.

2) Download Mavericks from the App Store

3) Run the installer. Tell it to install to the partition you just named Mavericks.

4) Wait

5) Wait some more

6) You're done after three reboots.

Edit: should install in Mavericks? As in you're not sure? Because this is a whole hour (or more, depending on Internet speed) of rigmarole to go through for something you're unsure about. If you have a capable phone (most iOS, Android, and WP7/7.5/8 phones), why not just do internet tethering?

It won't let me install it! It comes up with a message in the App Store that says "We could not complete your purchase. OS X 10.10 is already installed on this computer. Are you sure you want to download OS X 10.9?" with the options "Learn More" or "OK", and OK doesn't do anything! What now?

 

[Bruno09]

You should be able to download Mavericks from the "Purchases" tab.

 

[CaffeinatedNoms]

You should be able to download Mavericks from the "Purchases" tab.

Oh, and in certain odd circumstances you might have to hold down option when you click the Purchases tab. This sometimes helps if it says 'installed' and won't let you get another copy of the installer.

 

[Weaselboy]

Or can I create a duplicate of Yosemite on the HDD in the separate partition, and then use Time Machine to take it back to Mavericks?

If that TM backup was made with Mavs, it is pretty easy to just restore from there.

Attach the TM disk and option key boot to it. You will see a recovery screen. Assuming you already have the partitions setup correctly, just click restore and scroll back in time on the TM disk to where you still had Mavs then point it to the blank partition you want to put Mavs on and away you go. This will put the Mavs OS and all your apps and data back.

 

[AppleFan22]

I've done it!

I finally did it, after an online chat with Apple Support (which lied to me, and was quite frankly, useless). This is how you do it:

- Make sure you have backups of your disk pre-Yosemite.
-Partition the BACK UP disk with enough room to back up Yosemite
-Change the backup disk to the new partition and back up Yosemite (just in case it doesn't work.
-Now that you have both versions (Mavericks or older and Yosemite), partition the INTERNAL disk, about halfway, depending on what you're going to be doing.
- (Optional, but useful) Rename the partitions to Mavericks and Yosemite, as there is no way to tell when booting into them (Disk Utility may say that it has renamed the new one Macintosh HD 2, but it will just be Macintosh HD) An easy way of doing this is to just open the partition in Finder. The one that has your user name with the house icon is the one you're using
-Shut down the computer and boot into OS X utilities (⌘ + R after pressing the on button)
-Select Restore from Time Machine
-Choose the back up from Mavericks
-Choose the partition you want to install Mavericks on
-Let it do the restore.

That should be it. When booting into a different partition, hold down the Option/Alt key. You'll see the two partitions, along with two recovery partitions (Recovery 10.10 & Recovery 10.9).

It will take some time, depending on how much data is on your HDD. I hope someone finds this useful!