A few questions:
- Do you have an external hard drive with backup of the internal hard drive? If not it might be a good idea to try and get one incase you have to erase the internal hard drive...a good source is OWC, I have three of their Mercury Pro Elite 2 TB drives.
- Have you tried starting up in Safe Mode - startup holding the shift key, if you get a good startup then there may be issues with applications of extensions that Disk utility cannot resolve.
- If there is physical damage to the hard drive, the only options will be a new hard drive or an erase and install of the operating system, and all applications, so that the bad sectors can be avoided. This step should not be done until you have a backup of the drive.
Another idea: You might be able to fix this by running fsck in Single User mode. You would repeat this until possibly it is able finally to make the repairs. It's worth a try anyway.
Use fsck if necessary
I would agree with WZZZ, if you can safe boot then at the command prompt type /sbin/fsck -fy noting that there is a space between fsck and -fy...read the messages you get and when it stops finding errors, may take a couple times running fsck, then exit and reboot.
Disk Utility runs fsck behind its nice graphic interface, which is why the kb article says it really isn't necessary, but with problems like you are having it is a way of getting around the need for a full graphical system boot.
Hi Ralph and WZZZ,
The backup I have is on an external drive, the problem is that is not very updated, I have several files I didn't back-up for a while.... My bad.
So if I well understood, I power it up by holding down the shift key.
If the Mac starts successfully in safe mode, than I can copy my files to the external drive, right? And than perform the fsck (what's single User?)
If the Mac doesn't start in safe mode too, than means it is a hardware failure??
Single User Mode statup explanation. If you get a good startup in safe mode, you should be able to copy material to your external drive. But if the damaged file systems are the ones that are causing problems starting up, well they will still be a problem. Anyway, try the safe mode startup and see what happens. If all goes well try to copy your important material. Then do the single user startup and run fsck to see if that can clean things up for you.
If the Mac starts up successfully in Safe Mode, that means the drive is repaired. Give it much longer to boot in Safe Mode than with a regular boot. In that case, you can make a new backup. But in what form is the backup, Time Machine, a bootable clone or just files and folders copied over?
If it won't Safe Boot, that means you go onto booting into single user mode. Hold CMD-S keys down at startup, then follow the directions for fsck in the article I linked. single user will present you with a special screen that has only text. You may need to run fsck a number of times before the drive is repaired, if it's going to be repaired at all this way.
If it doesn't start in Safe Mode (not single user) that doesn't necessarily mean a hardware failure.
Performed twice fsck -fy, always I/O error.
[ERrType IO] [ErrNo 5] [IOTypre Read] [PBlkNum 27883664] etc.....
It makes it twice and than it starts fsck_hfs,
Returns Invalid node structure, I/O Error.
EXITED WITH SIGNAL 8
My backups are in time machine formats.
If I choose to reinstall OSX from the recovery HD, will it format the Partition?
If I start up the Mac by an external HDD, will I get access to the partition of the internal HDD?
If you start up from the recovery HD, one of the options is to do an erase and install which will sanitize the drive, and then restore from the TM backup. If you can start from an external drive, a clone of the internal, you will be able to see the internal hard drive and open it. You can copy material, as long as it isn't eamaged, to the external drive.