Q: Disk shows invalid code
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Sep 5, 2016 7:56 PMby Loner T,Do not further re-partition or modify the disk in any way, otherwise you will lose information. You have a corrupted GPT and possible a corrupted MBR.
Post the output of
sudo gpt -vv -r show /dev/disk0
sudo fdisk /dev/disk0
sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C
Bootcamp resizing is not supported by Apple. Please describe in a bit more detail the exact steps you used to try and resize the partitions.
Do you have backups of OS X and Windows and your original GPT and MBR?
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Sep 5, 2016 8:37 PMby clarkfromtopeka,Thanks for offering to help. Here is the info you requested:
clarks-imac:~ clark$ sudo gpt -vv -r show /dev/disk0
Password:
gpt show: /dev/disk0: mediasize=960197124096; sectorsize=512; blocks=1875385008
gpt show: /dev/disk0: Suspicious MBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 1875385007
start size index contents
0 1 MBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 1811206328 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
1811615968 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1812885504 62498816 4 MBR part 7
1875384320 655
1875384975 32 Sec GPT table
1875385007 1 Sec GPT header
clarks-imac:~ clark$ sudo fdisk /dev/disk0
Disk: /dev/disk0 geometry: 116737/255/63 [1875385008 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>
2: AC 1023 254 63 - 1023 254 63 [ 409640 - 1811206328] <Unknown ID>
3: AB 1023 254 63 - 1023 254 63 [1811615968 - 1269536] Darwin Boot
*4: 07 1023 254 63 - 1023 254 63 [1812885504 - 62498816] HPFS/QNX/AUX
clarks-imac:~ clark$ sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C
[The dd command returned nothing. ]
It all started when I tried to increase the size of Bootcamp using DU. I expanded the Bootcamp partition by 50GB. At that point Bootcamp was no longer visible when I restarted the iMac. After that I've tried all kinds of things using gpt and gdisk. I eventually got Bootcamp to be bootable but I know I still have problems.
I have backups of OS X. I have the important Windows files backed up but I only use it for gaming so they are not important. It would be fine with me if you felt the best thing is to delete the Windows partition and start over. If so, I would like advise on now to best delete the partition.
I do not have backups of the MBR or GPT.
Thanks again for your help.
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Sep 6, 2016 4:10 AMby Loner T,Can you post the output of
diskutil list
diskutil cs list
The MBR and GPT are in sync. Did you manually modify one or both to give them the same layout? You may need Testdisk eventually. Was Windows Disk Management also used to try an correct the problem?
Can you use Gdisk and the 't' command and change the partition type for last entry?
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Sep 6, 2016 7:04 AMby clarkfromtopeka,Here is the additional info you requested:
clarks-imac:~ clark$ diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *960.2 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_CoreStorage iMac OSX 927.3 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
/dev/disk1 (internal, virtual):
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS iMac OSX +927.0 GB disk1
Logical Volume on disk0s2
1E336067-9D1F-420E-BEA8-8627B08D99D3
Unlocked Encrypted
clarks-imac:~ clark$ diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group A448A397-80E2-4372-940B-4E0DEC7846A3
=========================================================
Name: iMac OSX
Status: Online
Size: 927337639936 B (927.3 GB)
Free Space: 12546048 B (12.5 MB)
|
+-< Physical Volume 714A4831-3FB4-4AC1-8EA5-CACEED76C8CE
| ----------------------------------------------------
| Index: 0
| Disk: disk0s2
| Status: Online
| Size: 927337639936 B (927.3 GB)
|
+-> Logical Volume Family 5E055ADE-DC25-4330-8F12-0AB1B9BED049
----------------------------------------------------------
Encryption Type: AES-XTS
Encryption Status: Unlocked
Conversion Status: Complete
High Level Queries: Fully Secure
| Passphrase Required
| Accepts New Users
| Has Visible Users
| Has Volume Key
|
+-> Logical Volume 1E336067-9D1F-420E-BEA8-8627B08D99D3
---------------------------------------------------
Disk: disk1
Status: Online
Size (Total): 926968578048 B (927.0 GB)
Revertible: Yes (unlock and decryption required)
LV Name: iMac OSX
Volume Name: iMac OSX
Content Hint: Apple_HFS
==========================================================
I first tried this:
sudo fdisk -e /dev/disk0
p
setpid 4
07
flag 4
p
write
y
I was unable to write so I booted from an external drive. At that point I think those commands were successful.
Then I tried to synchronize them using gdisk after reading this: http://sidecar.twocanoes.com/forums/index.php?p=/discussion/770/bootcamp-partiti on-not-shown-in-startup-pane-after-maver…
Throughout all my misadventure, I was never able to change the results of fdisk and gpt. I printed out their contents when I started and they haven't changed.
Thinking back, I wonder if I was actually able to change the partition size. When I went into DU, I dragged the bootcamp partition from something like 30GB to around 80GB. DU worked on it for a while, but when it was done the size had not changed.
I am unsure now at what point I was able to boot from the Bootcamp drive. I'm sorry I am so vague. I worked on this for hours yesterday and I don't have good notes. My browser history shows the dozens and dozens of web sites I visited. ARGGG!
I never used Windows Disk Management.
Neither the gdisk 't' command nor the gdisk 'd' command work. They only allow me to change the first 3 partitions, not the 4th which is Bootcamp. See below:
Command (? for help): p
Disk /dev/disk0: 1875385008 sectors, 894.3 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 581992C7-3743-44D8-9945-2616020AAAE9
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1875384974
Partitions will be aligned on 8-sector boundaries
Total free space is 62499477 sectors (29.8 GiB)
Number Start (sector) End (sector) Size Code Name
1 40 409639 200.0 MiB EF00 EFI System Partition
2 409640 1811615967 863.7 GiB AF05 iMac OSX
3 1811615968 1812885503 619.9 MiB AB00 Recovery HD
4 1812885504 1875384319 29.8 GiB FFFF BOOTCAMP
Command (? for help): t
Partition number (1-3):
==============================================================
Do you think it would be best to just delete the bootcamp partition. I can have a new Win 7 loaded back in an hour. And I have a complete backup of my files there. If so, what would be the best way to do this? I should note that Bootcamp Assistant no longer knows there is a bootcamp partition, so deleting it with BA is not an option. The only way I know to delete it is using DU. Note, I just checked and it does not appear that DU is working either. It no longer shows the bootcamp drive either! ARGGGG.
I have a complete Time Machine backup. And I have backups of my critical data folders, but I am going to do a complete using Carbon Copy Cloner. I think I see a fresh install in my very near future.
Thanks again for all your help!
One other thing. Three months ago I replaced the HD in my early 2009 iMac with a SSD. Since then my computer locks up for 20 or 30 seconds when it is first booted or woken after sleep. You have any idea what causes this? If I am going to have to reinstall, I might as well try to fix this problem too.
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Sep 6, 2016 7:15 AMby Loner T,The Fdisk command only changes the MBR, it does not change the GPT.
Instead of the 't' command, let us look at the output of
sudo gpt -vv -r show /dev/disk0
Do not delete Bootcamp yet, till we look at the GPT.
What type/brand of SSD did you use when you replaced the HDD? Can you check System Report -> SATA for SATA speeds and negotiated speeds?
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Sep 6, 2016 7:26 AMby clarkfromtopeka,clarks-imac:~ clark$ sudo gpt -vv -r show /dev/disk0
Password:
gpt show: /dev/disk0: mediasize=960197124096; sectorsize=512; blocks=1875385008
gpt show: /dev/disk0: Suspicious MBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 1875385007
start size index contents
0 1 MBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 1811206328 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
1811615968 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1812885504 62498816 4 MBR part 7
1875384320 655
1875384975 32 Sec GPT table
1875385007 1 Sec GPT header
I just compared this with what I printed before I started. No changes found.
Here is the system report for SATA:
NVidia MCP79 AHCI:
Vendor: NVidia
Product: MCP79 AHCI
Link Speed: 3 Gigabit
Negotiated Link Speed: 1.5 Gigabit
Physical Interconnect: SATA
Description: AHCI Version 1.20 Supported
OWC Mercury Electra 3G SSD:
Capacity: 960.2 GB (960,197,124,096 bytes)
Model: OWC Mercury Electra 3G SSD
Revision: N1007C
Serial Number: OW1603041001A526E
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Medium Type: Solid State
TRIM Support: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
EFI:
Capacity: 209.7 MB (209,715,200 bytes)
BSD Name: disk0s1
Content: EFI
Volume UUID: 0E239BC6-F960-3107-89CF-1C97F78BB46B
disk0s2:
Capacity: 927.34 GB (927,337,639,936 bytes)
BSD Name: disk0s2
Content: Apple_CoreStorage
Recovery HD:
Capacity: 650 MB (650,002,432 bytes)
BSD Name: disk0s3
Content: Apple_Boot
Volume UUID: EE7AAD83-563F-311E-BBF6-7AA245E7206D
==================================================
With respect to deleting the bootcamp partition, since it no longer shows up in Bootcamp Assistant or DU, I don't know of any way to delete it. That's why I am preparing for a full reinstall.
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Sep 6, 2016 8:09 AMby Loner T,Let us first try to correct the GPT. We can create a new blank GPT and create partition table by hand. If you have El Capitan, please disable SIP using Local Recovery (Command+R) and csrutil disable, otherwise Gdisk write will fail.
The following steps create a new GPT and overwrite the current MBR. GPT Fdisk (Gdisk) uses single character commands. The text in parentheses is for explanation purposes.
sudo gdisk /dev/disk0
o (Create a blank GPT)
x (Experts Menu)
l (Character 'L' - set sector alignment)
1 (digit 1 - set alignment to 1 sector)
m (Main Menu)
n (New)
1 (Partition 1)
40 (Start)
409639 (End)
EF00 (EFI)
n (New)
2 (Partition 2)
409640 (Start)
+1811206328 ( Use '+' for size - End)
AF05 (CoreStorage - OSX Partition)
n (New)
3 (Partition 3)
1811615968 (Start)
+1269536 ( Use '+' for size - End)
AB00 (Recovery HD)
n (New)
4 (Partition 4)
1812885504 (Start)
+62498816 ( Use '+' for size - End)
0700 (Bootcamp)
p (Print)
w (Write)
y (Confirm write)
q (Quit Gdisk)
Reboot. Test for OSX boot. Check if the Windows partition is visible in Finder and you can see Windows files.
Once this is tested, we will re-create the MBR as the next step. Please check the values to ensure there are no values which are incorrect.
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Sep 6, 2016 8:23 AMby clarkfromtopeka,OK, I will do this after I complete my bootable backup and test it. That should take an hour or two to complete.
Am I correct that if something goes wrong on the above procedure, it could make ALL partitions unbootable...it's not just messing with the Bootcamp partition. Right?
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Sep 6, 2016 8:32 AMby clarkfromtopeka,"Updated AF00 to AF05 to support CS"
What are the ramifications of this? Just googling a bit, I see CS was introduced in Lion. Am I not using it now? If not, why did it not get installed when I did fresh installs of all the new OSs since Lion. I always do fresh installs. I most recently did a fresh install when I installed the SSD.
Did you see anything in my SATA System Report that looked odd?
Thanks again for your ongoing help!!!
Clark
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Sep 6, 2016 9:11 AMby Loner T,clarkfromtopeka wrote:
Am I correct that if something goes wrong on the above procedure, it could make ALL partitions unbootable...it's not just messing with the Bootcamp partition. Right?
WE are not modifying any data on the disk, but just the partition table. If something goes wrong, we can use an external bootable OSX disk or Internet Recovery, as appropriate .
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Sep 6, 2016 3:43 PMby clarkfromtopeka,It worked pretty well. The computer still boots and I can see the Bootcamp partition in Finder. Also Bootcamp assistant know knows there is a bootcamp partition and I can use BA to delete it later if I need to.
There is one thing wrong. It boots VERY SLOW. It takes 45 seconds from the gong to until the login is shown. That used to be almost instantaneous. But there used to be a lockup sort of delay after I entered my login while the desktop was being loaded. That now seems to be gone. I suppose all this means there is something wrong with the SSD. I just noticed that the System Report now shows different info about the SSD:
NVidia MCP79 AHCI:
Vendor: NVidia
Product: MCP79 AHCI
Link Speed: 3 Gigabit
Negotiated Link Speed: 3 Gigabit
Physical Interconnect: SATA
Description: AHCI Version 1.20 Supported
OWC Mercury Electra 3G SSD:
Capacity: 960.2 GB (960,197,124,096 bytes)
Model: OWC Mercury Electra 3G SSD
Revision: N1007C
Serial Number: OW1603041001A526E
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Medium Type: Solid State
TRIM Support: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
EFI:
Capacity: 209.7 MB (209,715,200 bytes)
BSD Name: disk0s1
Content: EFI
Volume UUID: 0E239BC6-F960-3107-89CF-1C97F78BB46B
disk0s2:
Capacity: 927.34 GB (927,337,639,936 bytes)
BSD Name: disk0s2
Content: Apple_CoreStorage
Recovery HD:
Capacity: 650 MB (650,002,432 bytes)
BSD Name: disk0s3
Content: Apple_Boot
Volume UUID: EE7AAD83-563F-311E-BBF6-7AA245E7206D
BOOTCAMP:
Capacity: 32 GB (31,999,393,792 bytes)
Available: 604.3 MB (604,323,840 bytes)
Writable: No
File System: NTFS
BSD Name: disk0s4
Mount Point: /Volumes/BOOTCAMP
Content: Microsoft Basic Data
Volume UUID: 29C3738A-5FA6-40E7-AFF2-05003BF5423C
I notice the speed is now 3GB.
I have one more question....once you give me the final instructions and I setup the MBR, how will I increase the partition size for Bootcamp? Will I need to delete bootcamp using Bootcamp Assistant then recreate it larger, then reinstall Windows?
LonerT, again, I thank you for your help and patience. I see you spend a lot of time helping people. You must be a saint.
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Sep 6, 2016 4:07 PMby Loner T,clarkfromtopeka wrote:
It worked pretty well. The computer still boots and I can see the Bootcamp partition in Finder. Also Bootcamp assistant know knows there is a bootcamp partition and I can use BA to delete it later if I need to.
Excellent.
There is one thing wrong. It boots VERY SLOW. It takes 45 seconds from the gong to until the login is shown. That used to be almost instantaneous. But there used to be a lockup sort of delay after I entered my login while the desktop was being loaded. That now seems to be gone.
Can you run NVRAM and SMC Reset and test?
Reset the System Management Controller (SMC) on your Mac - Apple Support
How to Reset NVRAM on your Mac - Apple Support
I suppose all this means there is something wrong with the SSD. I just noticed that the System Report now shows different info about the SSD:
NVidia MCP79 AHCI:
Vendor: NVidia
Product: MCP79 AHCI
Link Speed: 3 Gigabit
Negotiated Link Speed: 3 Gigabit
Physical Interconnect: SATA
Description: AHCI Version 1.20 Supported
OWC Mercury Electra 3G SSD:
Capacity: 960.2 GB (960,197,124,096 bytes)
Model: OWC Mercury Electra 3G SSD
Revision: N1007C
Serial Number: OW1603041001A526E
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Medium Type: Solid State
TRIM Support: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
EFI:
Capacity: 209.7 MB (209,715,200 bytes)
BSD Name: disk0s1
Content: EFI
Volume UUID: 0E239BC6-F960-3107-89CF-1C97F78BB46B
disk0s2:
Capacity: 927.34 GB (927,337,639,936 bytes)
BSD Name: disk0s2
Content: Apple_CoreStorage
Recovery HD:
Capacity: 650 MB (650,002,432 bytes)
BSD Name: disk0s3
Content: Apple_Boot
Volume UUID: EE7AAD83-563F-311E-BBF6-7AA245E7206D
BOOTCAMP:
Capacity: 32 GB (31,999,393,792 bytes)
Available: 604.3 MB (604,323,840 bytes)
Writable: No
File System: NTFS
BSD Name: disk0s4
Mount Point: /Volumes/BOOTCAMP
Content: Microsoft Basic Data
Volume UUID: 29C3738A-5FA6-40E7-AFF2-05003BF5423C
I notice the speed is now 3GB.
The 3GB is correct. I was a bit surprised to see 1.5GB speed. The Sandforce controller can be fussy. You may want to check with OWC and some tuning. Some have tried to enable TRIM, but it may not be very beneficial.
I have one more question....once you give me the final instructions and I setup the MBR, how will I increase the partition size for Bootcamp? Will I need to delete bootcamp using Bootcamp Assistant then recreate it larger, then reinstall Windows?
The MBR can be setup using Gdisk. The Apple-supported method of resizing is to remove/re-install but third-party tools like Winclone or CampTune can do this without losing your installed Windows.
Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 10. Accept all other defaults that Gdisk offers. Please see the sample Q&A as an example. These steps can be repeated if you make a mistake before you get to Step 12, otherwise start from Step 1 for these steps. Step 6 has numbers which are typed with a space between the numbers. Please see the sample Q&A before you execute these steps.
- Sudo gdisk /dev/rdisk0
- P (Print list of parts)
- R (Recover)
- O (print current Hybrid MBR)
- H (chooses Hybrid)
- Partitions numbers to be hybridized: 2 3 4
- Y (Good for GRUB question)
- N (part 2 boot flag)
- N (part 3 boot flag)
- Y (part 4 boot flag make NTFS bootable partition)
- O (print current Hybrid MBR)
- W (Write the new MBR)
- Y (Yes! write the new MBR)
- Reboot
Here is sample Q&A for this section. Please notice the Press Enter/Return.
Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y
Creating entry for GPT partition #2 (MBR partition #2)
Enter an MBR hex code (default AF): Press Enter/Return
Set the bootable flag? (Y/N): N
Creating entry for GPT partition #3 (MBR partition #3)
Enter an MBR hex code (default AB): Press Enter/Return
Set the bootable flag? (Y/N): N
Creating entry for GPT partition #4 (MBR partition #4)
Enter an MBR hex code (default 07): Press Enter/Return
Set the bootable flag? (Y/N): Y
Test 1 - Does Bootcamp Volume show up in Finder?
Test 2 - Can you see files in Bootcamp Volume?
Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?
Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.
