Partitioning HD problems

Don't know if this is the right place for this post!

I tried partitioning the HD on my iMac. I had El Capitan on the larger partition & 10.6.8 on the smaller part. Hey, I'm cool.... until I tried to change the startup from one to the other. I put the 10.6.8 OS on last so that's where I was stuck. It would not recognize both partitions. It would only recognize the smaller section with 10.6.8. So to get out of the situation & put El Capitan on both partitions to be able to undo the partitioning. Vat deed I do wrong?

Do you have a backup of your files? Did your iMac come with 10.6.8 on it? If the iMac is newer it will not run 10.6.8.

If you have a backup of your files, start over by partitioning the hard drive with the 10.6 disc in the drive. Then reinstall which ever OS you want first.

iMac runs fine on 10.6.8.

1. I upgraded it to El Capitan & it ran fine. 2. Then I created a two partitions. It ran fine & both partitions showed on HD. 3. Used original 10.6 startup discs to install 10.6 on the empty partition. After installing 10.6 it restarted on 10.6, but did not read/show El Capitan in Preferences - Startup Disk, so I can't choose to start computer with with El Capitan. My purpose was to be able to choose either OS/partition to run the computer so as to be able to use 10.6.8 & the older apps that will only run with 10.6.8. What did I do wrong!

Try holding down Option as it boots---keep it held down until you get a screen showing your options. There should be two or three--one for El Cap, maybe one for Recovery El Cap and the last one for 10.6.8. Boot from El Cap and set the preferred boot disk from there. That should do it.

Mr. D from my memory I recall having read, some time ago now, it may be necessary to format the entire drive, set up Snow Leopard first, update and backup, then do the partition and install El Capitan then. Something to do with recognition of the older operating system first I think.

If you must have OS X.6 maybe virtualisation is the way to go with a server edition. Have a read of this:-


https://discussions.apple.com/thread/7058131?tstart=0

Thanx for the ideas guys!

I noticed that the reference seemed to be saying I could use install discs to put 10.6 on an external HD drive & boot my iMac off the external HD???? Do you think that would work or would it also require reinitializing the iMac HD to be able for Startup to read both OS's?

Would I have to install the "server edition" of 10.6 for Startup to recognize both OS's?

I'm going to try loading 10.6 on my external HD! If iMac will start on my external HD that will solve my problem! Here goes!

Never mind... it worked! I can use El Capitan on the iMac HD & 10.6.8 on the external HD. I may have to start with the "Option Key" down (not sure yet) but that's no biggy! See...., you can teach a '74 old dog/teacher new tricks!

Thanx all! Mr. D

Holding the Option key down is how you select which boot system to use. So it's not that you "may" have to use it, it is that you "will" have to use it. That's why I suggested it to find the other partition. Booting from external is SLOOOOOOOW, as you have probably already found out. Given you've had success now with external have you "fixed" the internal drive to recover the space from the two partitions, or are you going to give it another go?

Yes, I have recovered the space & only have one partition with El Capitan on it.

From your understanding, what is the best way to create two partitions & have them recognized by my iMac. Do I need to erase the entire HD before I create partitions, or can I leave El Capitan & my files on the HD when I create a second partition. Obviously it would be better to have 10.6.8 on a partition to speed up things like burning videos using 10.6.8 applications. Right now everything is on an external HD using firewire. I assume the speed of operation will be a combination of the processor speed of the iMac & the speed of the Firewire connection. I don't know how much faster it would be with everything on the iMac in a partition VS using an external HD using Firewire. Obviously having everything on the iMac HD will be faster..... I don't know if the extra speed will be that noticeable. The only critical use speed issue is when burning DVD's.

Mr. D, you asked two different questions: What is the BEST way and do you NEED to erase the drive. The two answers are mutually exclusive. The BEST way is to erase the entire drive, partition it as you want it, install the two operating systems, set one as default and then use Option-Boot to get to the other. (BTW, if you do that, put the preferred system in the first partition as the OS will default to that one anyway.)

Do you HAVE to do that? Maybe not, if the El Cap is on the first partition and you use a partitioning tool to shrink that first partition to make room for the second. But there are some obvious risks to doing it that way, including the possible loss of data on the shrinking partition.

As for speed, the biggest difference will be at boot and at any operation that needs to read/write to the boot drive. Firewire interface speed is either 400MB/s or 800MB/s, and the internal drive interface is either 6GB/s or 3GB/s, depending on the system. So the external interface is somewhere between 3.75 and 15 times faster than Firewire external. The speed is also dependent on the read/write speed of the drive itself, but if we just look at the interface, the internal is clearly faster. Is that significant to you? Where you will see the speed difference the most is in boot and application launch times. Plus, if the application uses the boot drive for "scratch" storage in its operation, that will be slower, too. But if you don't use it that often and can put up with the slowdown when you need to do it, it can work fine. One way to speed things up is to make the external an SSD, thereby making the I/O channel the only bottleneck by having such a fast storage. Of course, that SSD could make the internal really fly, too, so my personal preference would be to have the SSD internal for that everyday speed. But it's up to you how you want things.

BTW, burning DVDs won't really be affected because the burning itself is the driving factor. But if you are doing graphic rendering and the graphic application needs a lot of scratch space in the rendering process, you probably will be greatly affected by the Firewire.

Thanx MacInWin. Great answer!

I'm finding the best way to deal with my issues it to find El Capitan friendly programs. The only issue is that I have to relearn how to use these new problems. The one type of program I cannot find is a "simple" video editing program. If you compare the old "iMovie video editing apps" that were around back in at the beginning of OS 10.0 they were very simple & intuitive to use. Newer iMovie versions are hard to understand & seem to be created for people wanting to create Hollywood movies rather than edit "home movies". Apple should have simple apps for the average user!

So the external interface is somewhere between 3.75 and 15 times faster than Firewire external.

Click to expand...

I meant to say that the INTERNAL interface is faster than the Firewire external, but you got the gist of it.

You are right that the simpler applications have morphed into much more complex ones, making the simple tasks harder to accomplish. But that's the way the world works these days.