During my upgrade from 10.8.5 to Mavericks on my imac I ran into some serious issues. I will try to break it down here:
- The mavericks installation failed, indicated damaged hard drive (a quite common problem, it seems, although there does not seem to be the one solution for it).
- When trying to revert to 10.8, I had problems, with safe mode not running faulty, hard drive repair via disk utility impossible and disk utility suggesting wiping the HD.
- I decided to go ahead and erase the HD and do a clean reinstall.
- Trying to reinstall 10.8 from recovery mode (cmd+r at login, or cmd+alt+r for internet recovery mode) failed. It always suggested to restart the installation.
I do not have a time machine backup - all critical data is saved elsewhere and I do possess a disk image created with superduper on a network drive. Only this does not help in the present situation.
So in lack of a better alternative I created a Mavericks installation partition on a USB HD and tried to clean install Mavericks from there, as described by option 1 here:
During the installation an error occured. Something along the lines of "could not creat recovery HD". I found that some people had overcome this issue by:
a) changing their main partition size to free some space for the creation of a new recovery HD.
I tried this from recovery mode disk utility, it did not have an effect, and I returned to only having one (visible) partition on my HD.
b) using diskutil to wipe the recovery HD and merge it with the main HD partition:
I tried this, but then the step of merging failed, namely (with different names):
diskutil mergePartitions HFS+ MacHD disk0s3 disk0s4
I do not remember the exact error message.
- Both the Mavericks installer on my USB HD and the 10.8 installer in recovery mode refuse to install on my main partition:
"OS X cannot start up from this disk" / "This disk cannot be used to start up your computer"
- Trying to change partitions from Disk utility as described here fails:
Presumably this can be repaired by using diskutil in the right way. Only I have no clue how.
I am slightly distressed by this whole thing and would appreciate any help! :/
The imac is rather new, with no Bootcamp partition or anything nonstandard.
This seems to be the usual fix:
This does not work, as disk utility does not allow me to resize partitions anymore.
Message was edited by: mmand
I got my issue solved. A reason for the problem seems to be that I turned in Filevault inadvertently at some point.
For future reference–there seem to be two possible ways:
1. Using the "diskutil" terminal command:
- Boot and hold cmd+r or cmd+alt/option+r for recovery mode or internet recovery mode (equivalent, the latter may be slower depending on your connection)
- Open Terminal from Utilities menu
- Enter "diskutil cs list"; I got the following output:
me-mas709:~ mext$ diskutil cs list
CoreStorage logical volume groups (1 found)
+-- Logical Volume Group 56374D16-C7A1-47D7-9627-5F93E61E13C9
Name: Macintosh HD
Size: 2999733223424 B (3.0 TB)
Free Space: 0 B (0 B)
+-< Physical Volume AD7909DD-1F2E-4F48-848A-A7FB741BDD60
| Index: 0
| Disk: disk0s2
| Status: Online
| Size: 2999733223424 B (3.0 TB)
+-> Logical Volume Family 148BBF17-B993-4F5E-BEA9-144776CD63C1
Encryption Status: Unlocked
Encryption Type: None
Conversion Status: NoConversion
Conversion Direction: -none-
Has Encrypted Extents: No
Fully Secure: No
Passphrase Required: No
+-> Logical Volume 135EAF79-E66A-444D-B954-9DB8E94783FE
Size (Total): 2999414448128 B (3.0 TB)
Size (Converted): -none-
LV Name: Macintosh HD
Volume Name: Macintosh HD
Content Hint: Apple_HFS
- Type the following commands into terminal (with the appropriate volume names from the previous step):
diskutil cs deleteVolume 135EAF79-E66A-444D-B954-9DB8E94783FE
diskutil cs delete 56374D16-C7A1-47D7-9627-5F93E61E13C9
- Still in recovery mode, open Disk Utility. It should show the HD without any volumes on it. Go to Erase tab, rename the HD, select "Mac OS Extended [...]", apply.
- Run "Repair Disk" in Disk Utility to see if any errors occur.
- Reinstall the OS, migrate/copy data from your backup
2. Using the UNIX level dd command (this is what I used, worked for me):
- For this solution, you require a working OS X installation on a different (external) drive. In my case, the external drive was smaller than the internal one (where I tried to install), this may be necessary.
- From terminal in recovery mode (press and hold cmd+r on startup), type "diskutil list"
- From the output, identify the disk where you want to install OS X (in my case "disk0") and the disk where your working OS X is installed (here: "disk2")
- Run the command "dd if=/dev/disk2 of=/dev/disk0 bs=4096 conv=notrunc,noerror" with the appropriate disk names. This should create a 1-to-1 copy of the external disk (including all partitions) on the internal disk. This may take a while (took me 2 hours for a 80GB external USB HD). This solved the data structure issue on the internal disk.
- Once this is done, boot from the Internal HD. Run Disk Utility Repair Disk/Permissions. Reboot.
- In Disk Utility, expand the new cloned partition on your internal HD to the full size of the HD.
- You can then rename the partition with "
/usr/sbin/diskutil rename "Macintosh HD" "Mac Disk"" command in Terminal
- Update the OS or migrate / copy data as needed