bootcamp
Since trying to install Windows 7 on my iMac with Lion 10.7.4, using Boot Camp, I noticed that the login screen where it asks for the FileVault password is taking a lot of seconds to be displayed.
When I turn on the computer, after the sound only a blank screen is shown for a lot for seconds.
Even after removing the Windows partition using Boot Camp, this slow down persists.
Anyone with similar problem, or solution?
The small partition you've deleted is your on-board Recovery HD. But deleting it isn't the real reason why you can't boot. You hosed your GUID partition table by manipulating it from inside Windows 10.
The basic steps you have to execute are:
Preparation:
Restart to Internet Recovery Mode by pressing alt cmd R at startup.
The prerequisites are the latest firmware update installed, either ethernet or WLAN (WPA/WPA2) and a router with DHCP activated.
On a 50 Mbps-line it takes about 4 min (presenting a small animated globe) to boot to a recovery netboot image which usually is loaded from an apple/akamai server.
I recommend ethernet because it's more reliable. If you are restricted to WIFI and the boot process fails, just restart your Mac until you succeed booting.
Alternatively you may start from a bootable installer thumb drive (Mavericks or Yosemite) or a thumb drive containing a full system (Mavericks or Yosemite).
Modify GUID partition table:
First you should get an overview of your disks and the partition layout:
Enter diskutil list, diskutil cs list and gpt -r show /dev/disk0
diskutil list:
bash-3.2# diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partItion_scheme *251.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_CoreStorage 209.4 GB disk0s2
3: Microsoft Reserved 16.8 MB disk0s3
4: Microsoft Basic Data BOOTCAMP 41.4 08 disk0s4
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *1.3 GB disk1
1: Apple_partition_map EFI 30.7 KB disk1s1
2: Apple_HFS OS X Base System 1.3 GB disk1s2
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS Macintosh HD *209.0 GB disk2
/dev/disk3 - /dev/disk13 part of the Recovery System
diskutil cs list:
-bash-3.2# diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 017D5AE8-30F7-45E1-879E-BB02C0EC3DC1
=========================================================
Name: Macintosh HD
Status: Online
Size: 209371209728 B (209.4 GB)
Free Space: 35655680 B (35.7 MB)
|
+-< Physical Volume FB261C56-1F49-4690-9B15-8C4EAA4770B0
| ----------------------------------------------------
| Index: 0
| Disk: disk0s2
| Status: Online
| Size: 209371209728 B (209.4 GB)
|
+-> Logical Volume Family A62719EC-A4E5-4821-B7E0-831444CC3...
----------------------------------------------------------
Encryption Status: Unlocked
Encryption Type: None
Conversion Status: NoConversion
Conversion Direction: -none-
Has Encrypted Extents: No
Fully Secure: No
Passphrase Required: No
|
+-> Logical Volume D0DEC2A0-0E60-49B1-9758-40E7677A5346
Disk: disk2
Status: Online
Size (Total): 209000005632 B (209.0 GB)
Conversion Progress: -none-
Revertible: Yes (no decryption required)
LV Name: Macintosh HD
Volume Name: Macintosh HD
Content Hint: Apple_HFS
gpt -r show /dev/disk0:
bash-3.2# gpt -r show /dev/disk0
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 408928144 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
409337784 72
409337856 32768 3 GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE
409370624 80863232 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
490233856 863
490234719 32 Sec GPT table
490234751 1 Sec GPT header
Unmount the CoreStorage volume first and then the main disk:
diskutil umountDisk /dev/disk2
diskutil umountDisk /dev/disk0
then delete the Windows partitions on your main disk with gpt:
gpt remove -i 4 /dev/disk0
gpt remove -i 3 /dev/disk0
If you get an error "gpt remove: unable to open device '/dev/disk0': Resource busy" trying to remove a second (or third) partiton just repeat
diskutil umountDisk /dev/disk2
diskutil umountDisk /dev/disk0
After deleting or adding a partition with gpt the system sometimes|often|always tries to immediately mount all remaining partitions. If you get an error similar to "disk2 is not mounted" trying to unmount disk2, just continue with diskutil umountDisk /dev/disk0.
delete the GUID partition table and force create a new one:
gpt destroy /dev/disk0
gpt create -f /dev/disk0
add the EFI-partition and the Macintosh HD Logical Volume Group with gpt
gpt add -b 40 -i 1 -s 409600 -t C12A7328-F81F-11D2-BA4B-00A0C93EC93B disk0
gpt add -b 409640 -i 2 -s 408928144 -t 53746F72-6167-11AA-AA11-00306543ECAC disk0
disk0 and the CoreStorage should be mounted automatically after adding the second volume. Please check this with diskutil list and df. Your CoreStorage volume may have different DiskIdentifier now. After entering diskutil list to get the DiskIdentifier of your CoreStorage volume enter df and check if the file system is mounted. The output is similar to that one:
User$ df
Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on
...
/dev/disk13 6066780416 5444610552 621657864 90% 680640317 77707233 90% /Volumes/Macintosh HD
...
If the CoreStorage wasn't mounted earlier, you may mount it with diskutil mount /dev/disk13 (or whatever the DiskIdentifier of your CoreStorage Volume is).
open Disk Utility and verify/repair first the hard drive, then the CoreStorage volume. If the CoreStorage wasn't mounted earlier
Expand the CoreStorage volume:
expand the Macintosh HD Logical Volume Group to the full available size of your main disk:
diskutil cs resizeStack LVUUID size #LVUUID = Logical Volume UUID
In your case (just copy the UUID of the Logical Volume in the "diskutil cs listing" you got earlier and paste it here. The UUID below might be faulty because I OCRed your screenshot):
diskutil cs resizeStack D0DEC2A0-0E60-49B1-9758-40E7677A5346 0g
If you encounter an error like "Error: -69722: You can't perform this resize unless it has a booter (target partition is probably too small)" here, you have to revert your CoreStorage volume to a normal volume:
diskutil cs revert LVUUID
In your case:
diskutil cs revert D0DEC2A0-0E60-49B1-9758-40E7677A5346
Then quit Terminal by entering exit and open Disk Utility. Mount the volume Macintosh HD if unmounted and verify/repair it. Choose the hard disk and then the partition tab. Expand the volume with the slider to the full size of your hard disk.
Recreate Recovery HD
Reinstall Windows 10
If you run into problems please add a comment with @klanomath
my bad, I just needed to take the extra step of formatting the Boot Camp drive to NTFS:
(per: https://www.howtogeek.com/186907/how-to-install-windows-on-a-mac-with-boot-camp/)
Best Answer
The common cause is when the OS X EFI isn't selected in startup preferences (and then stored in NVRAM) so the system needs to read all drives before defaulting to the lowest numbered Mac volume.
A more oddball case would be if the kernel caches are somehow invalid and must be recreated which slows a boot sequence considerably.