Q: Hard drive error has lead to multiple issues on multiple machines
Hi,
We have several iMac's in the house and as there are a couple of machines involved in this query, I will number the machines and list their spec's at the bottom.
One of these recently started failing to boot (iMac 01), it was hanging on the grey screen with apple logo and loading wheel. After trying to restart several times, it would then show the loading bar progressing to ~1/4 of its length and then would shut down.
After booting into disk utility, (there is no recovery partition) and trying to verify & repair disk I am given an error saying that the disk could not be verified, and needs to be repaired (system check exit code is 8). When I try to repair, it said it could not be repaired and that I should back up my files and reformat the disk etc. At some point in time I recall it saying "invalid B Tree node size" - if that is of any use??
I decided to follow its advice and use Carbon Copy Cloner (CCC) to create a disk image of the original hard drive, by accessing it in target mode through a second iMac (iMac 02). (side note: at this point I was able to access the files and folders on iMac 01 through finder on iMac 02)
iMac 02 did not have enough available hard drive space to store the disk image, so I used an external hard drive plugged into iMac 02. This external hard drive is an archive of years of photos, videos and other information. I left CCC to create the disk image for several hours, and when it was ~95% complete, it failed due to an unknown error.
After this, I decided that the best course of action would be to manually copy just the most important files from iMac 01 to the external hard drive via iMac 02. However, I was now unable to access the folders on iMac 01 - they had the little red circle in the bottom corner and I was told that I did not have the necessary permissions required to access the files. In addition, I now could not even access the drive (I could see it in finder, and see the usage in disk utility etc. but when trying to open the drive I encounter: "The folder “Archive” can’t be opened because you don’t have permission to see its contents."
Assuming it was something to do with permissions on iMac 02, I stupidly changed the permissions on the startup disk. This led to multiple errors when trying to access files. I decided that switching it off and on might resolve the errors, but now iMac 02 just hangs on the apple logo and wont boot.
In an attempt to resolve this, I am currently using a third iMac (iMac 03) to access iMac 02 in target disk mode, and am repairing the permissions on the startup disk. It has been going for over 48 hours now, and is still saying 9 hours remaining. Reading the information in the repair permission process, there is a lot of "Permissions differ on **filename**, should be 0, user is 501" but it seems to be progressing through the files - if very slowly.
I read somewhere that CCC changes the permissions on the destination hard drive to match those of the source. If so, when i plug it into iMac 01 (the source) -Would I be able to access the incomplete disk image? or would it be unwise to attempt to restore iMac 01 from the incomplete disk image on the external hard drive?
I have verified the external hard drive using disk utility and found no issues.
I know there are a lot of different issues to contend with here, but the most critical is regaining access to the external hard drive. I am unable to change any of the permissions in the "get info" window, it says "The operation can't be completed because you don't have the necessary permission."
Please help, any advice would be greatly appreciated!
Spec information is limited due to iMac 01's limited boot ability, and iMac 02 being in target disk mode for the foreseeable future.
However I believe the spec's are as follows:
iMac 01
2009 iMac
3.06 Ghz Core 2 Duo
500GB Hard drive
16GB Ram
Running OS 10.10.4 Yosemite
iMac 02
2009 iMac
3.06 Ghz Core 2 Duo
500GB Hard drive
16GB Ram
Running OS 10.9 Mavericks (it was an old surplus machine that had not been run in a while - hence I am not sure of the exact OS it is running)
External hard drive
Western Digital
My Book Studio
1TB
iMac
Posted on Apr 4, 2016 4:32 AM