Can't install MAC OS X Lion - Macintosh HD "This disk cannot be used to start up your computer."

RJV Bertin wrote:

So all hints until now about resizing the install partition concerned a destructive resize?

No. If the reason for the 'cannot be used message' is an anomaly in the GPT partition scheme info on the drive that the installer objects to, this often can be fixed by moving the size tab for the partition in Disk Utility's "Partition" tab to change its size slightly & clicking the 'apply' button. This does not destroy any data. As part of the resize process, it updates the GPT partition scheme info, putting it in a form the installer will accept.

There are other reasons why the message might appear, so this won't always work.

I have had the same problem as everyone else in this thread and wanted to contribute the solution that worked for me. I sat down with Apple CS over the phone for 2 hours and ultimatley were able to move forward with the Lion install on my desired target disk.

The whole problem evidently stems from "ghost" partitions on my MacPro's HDs. Each had a small (134.2 MG) "ghost" partition that I had never seen previously. Perhaps Lion installed them, perhaps Fushion did -- who knows? (they are all WD HDs).

Anyway, I loaded the Snow Leopard Install disk and held "C" down during the install to bring up the option for disk utility during the install process (Obviusly did not re-install Snow Leopard). After identifying the ghosyt partition (it was in a ligher color grey than the main partition) and was labled something along this lines of "1sc1" -- something I had never seen previously nor named myself. Anyway, we erased that partition, closed disk utility, did not continue the Snow Leopard re-install. Next we re-started the computer, ejected the install disk and the proceeded to move forward with the Lion install. It worked!

I am still having bugs with mail and several Adobe programs no longer work, which is sveral hundred dollars down the drain, but I have Lion up and running.

So, I FINALLY got Lion to install.

I was getting the "This disk cannot be used to start up your computer." error when trying to upgrade. I tried almost every solution listed above without any success. I tried calling Apple Support, but they just told me that I would need to wipe my drive (both SL and Windows 7 bootcamp partitions), reinstall SL, then try upgrading to Lion again. I really didn't want to do this, so I kept trying.

My solution:

Reboot into my Paragon CampTune disk. This tool finally let me resize my partition (the native Apple tools gave me an error whenever trying to do this.) I rebooted into SL and the Lion upgrade worked for me. I'm now running Lion without any problems.

I hope this helps.

This has truely been a disapointing experience.

The hatter wrote:

I would clone the system no matter what.

And do a clean install of Lion after formatting.

Actually, I never update from my (main) boot disk onto the same disk, except for security updates. This has several advantages IMHO, if not only to avoid unnecessary free space fragmentation.

My usual upgrade strategy that always worked well is a step beyond that: I update a fresh clone of my main boot disk.That way, I can tackle all hairy details without fear for my production set-up, and then clone the new OS back to the main disk when I'm ready/satisfied.

This might also address any issues with incompatible partition schemes (and to get rid of the recovery partition when cloning back - once you have the habit of making backup clones, that partition is completely redundant I think).

But be careful because in normal mode, Disk Utility does not show the Recovery HD or the Disk0s1 (EFI volume).

You need to go into Debug mode and select "Show all partitions".

As mentioned in this thread, the EFI volume should not be deleted.

For the sake of simplicity and for all the space it takes, I think I would leave the Recovery HD alone.

Debug mode:

Who mentioned deleting the partition? When cloning, one usually works at the partition level, so the recovery partitions remains nicely where it is 😉

One of Apple's KB articles mentions that the recovery partition isn't required. Of course I don't know what happens when a cloned install doesn't find it.

You said "and to get rid of the recovery partition when cloning back - once you have the habit of making backup clones, that partition is completely redundant I think".

Sorry if I mis-understood you. It seems to be a delicate subject, partitions I mean😊

RJV Bertin wrote:

One of Apple's KB articles mentions that the recovery partition isn't required. Of course I don't know what happens when a cloned install doesn't find it.

As I understand it (which isn't all that well), FileVault 2 requires that the recovery partition be present on the boot drive. Otherwise, as best as I can tell there should be no problems if it is deleted or unrecognized by the cloned Lion partition for some reason.

So has any one relatively simple solution to this problem been found yet? I have downloaded Lion OS but haven't tried to install it after reading of this (I have a boot camp partition so i'm pretty sure I would have the same problems). I would return the OS until this is fixed but can't do that. So, I have Boot Camp, I have Lion, haven't tried to install it. What should I do before the installation?

Simply, copy the installer into another folder (because the original gets deleted after the instal). Clone your existing Snow Leopard and Boot Camp to an external disk, which is just good backup practice anyway. Then run the installer. Several million people have done this already, so you have a good chance it will work without a problem. If it does go wrong, you have a bootable backup.

You sure it was his neck and not some other part of the body with a hole in it? 😉

I have a WD 750GB drive in my Macbook and it runs just nicely. It has been formatted as GUID partition w/journaled HFS+ file system.

putnik wrote:

... Clone your existing Snow Leopard and Boot Camp to an external disk, which is just good backup practice anyway. Then run the installer...

on the external disk, which will give you an external 10.7 bootable media, without touching your main/production disk. Test it out at leisure, repeat the operation if required, if necessary wait for 10.7.2 or whatever when the OS is really ripe according to YOUR standards. And when you're really confident that you'll have no regrets moving to 10.7, you clone that external Lion over your internal snowcat.

Of course it helps to have your workfiles somewhere where you get at them from both boot disks without having to copy them back and forth (I actually have them on a separate partition, of which I also have clones). But even without that refinement there are very viable solutions to keep (for instance) work directories synchronised. I personally use Unison for that (http://www.cis.upenn.edu/~bcpierce/unison/docs.html ; the site with the OS X binaries seems to be down right now) but it is of course not the only solution.

I was trying to keep it simple, as requested🙂 Hope for the best and prepare for the worst...

spg29 wrote:

So has any one relatively simple solution to this problem been found yet?

There isn't one simple solution because there is more than one cause of the problems this discussion covers.

For example, if you get an error mentioning Time Machine, look for the "Backups.backupdb" folder on the volume you want to install Lion on. But if Time Machine isn't mentioned, there is no point in doing that because that folder isn't the cause of the problem.

If you get the generic 'cannot be used to start your computer' message, then it may be that just resizing the Mac OS volume slightly with Disk Utility will suffice -- or not. That will probably work if the cause is some non-standard entries in the drive's GPT format (usually caused by using non-Apple partitioning utilities, not Boot Camp Assistant itself), but it won't help if say the Mac OS volume's file system is damaged, or the drive isn't formatted as GPT to begin with.

And as already mentioned, just having a Boot Camp-created partition on your drive does not automatically mean you will have any problems installing Lion. Apple announced that Lion was downloaded over a million times in the first day of release -- if everyone that tried to install it on drives with a Boot Camp partition was having problems, you would not have to read about it here -- it would almost certainly have made the evening news! 😉

But as putnik said, hope for the best but prepare for the worst. It is always a very good idea to backup (or clone) your stuff before upgrading (or even just updating) your OS. The chances that something will go wrong are small, but why expose yourself even to a small risk if you don't have to?

Thanks to you and putnik for your replies.

I actually spent $300 buying Time Capsule a couple days ago just so I could back up everything from my comp as per suggestions to installing Lion. I need to backup anyway so it was a sound investment, especially since I have Murphy's Law seemingly embedded into everything related to computer instalations. After I started downloading Lion but before installing it is that I find about these problems, else I would have waited (I know, my mistake). You are right, everything might go smoothly, but given my personal history of bs happening when I try to install something simple (for example, doing the aforementioned partition was a pain in the *** because it turned out there's a problem specific to 27 inch iMacs) I am being very cautious. I am not computer savyy besides the basic stuff, I can follow recommendations on forums like this but that doesn't mean I know exactly what I'm doing, just that those are the steps.

I think I will give it a shot. Everything is backed up on the Time Capsule so I don't fear losing stuff, at least.