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GUIDE: Zap PRAM, Repair Permissions, & run FSCK
- Thread starter edesignuk
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i've just done this- caused further problems in os X!
i've just carried out the reset permissions and fsck from the terminal.
however, now the computer does not even start up! i hear the bong, and then nothing appears on the screen. it just stays black.
what could this be and how to resolve?
i've just carried out the reset permissions and fsck from the terminal.
however, now the computer does not even start up! i hear the bong, and then nothing appears on the screen. it just stays black.
what could this be and how to resolve?
tango472 said:
Can you hear your disk drive going? If so, it's possible your LCD's backlight is out.
Did the problems originate immediately after running fsck? Did you run it from single-user mode (and I do NOT mean from Terminal)?
here's a good article about why reparing permissions is useless (in the majority of situations) from the fine people of unsanity
http://www.unsanity.org/archives/000410.php
a good read from a good source
http://www.unsanity.org/archives/000410.php
a good read from a good source
I've found that people will do it anyway as a maintenance.
It makes them feel better about their computer, and there's a psychosomatic feeling that things are "running faster". It's not, but whatever makes you feel good, right?
It makes them feel better about their computer, and there's a psychosomatic feeling that things are "running faster". It's not, but whatever makes you feel good, right?
FaE, maybe start a new thread with specific details relating to your problem such as why you needed to reset the PRAM, what sort of computer you have, and when you get this behaviour. 
Fsck
Hello!
First, thank you for writing the very helpful guide. And the various Posts that accompanied it have clarified many minor questions that I had.
Second, I have been running FSCK for over a year, not from Disk Utilties' Repair function, but after booting into single-user mode (command + S).
At the start-up screen, the message on the screen is:-
Singleuser boot -- fsck not done
Root device is mounted read-only
If you want to make modifications to files,
run '/sbin/fsck -y' first and then '/sbin/mount -uw /
local host: /root#
So I have assumed that, if there were errors in the files, they would have to be modified and have routinely run those two extra commands before going to run the regular fsck -f at the final prompt.
Does it make any difference to the outcome?
Any information would be appreciated.
Hello!
First, thank you for writing the very helpful guide. And the various Posts that accompanied it have clarified many minor questions that I had.
Second, I have been running FSCK for over a year, not from Disk Utilties' Repair function, but after booting into single-user mode (command + S).
At the start-up screen, the message on the screen is:-
Singleuser boot -- fsck not done
Root device is mounted read-only
If you want to make modifications to files,
run '/sbin/fsck -y' first and then '/sbin/mount -uw /
local host: /root#
So I have assumed that, if there were errors in the files, they would have to be modified and have routinely run those two extra commands before going to run the regular fsck -f at the final prompt.
Does it make any difference to the outcome?
Any information would be appreciated.
UKnjb said:
I'm not sure I follow but fsck doesn't run automatically, even when loading into Single User mode.
mad jew said:I'm not sure I follow but fsck doesn't run automatically, even when loading into Single User mode.
I power on the computer (PowerMac G4 with Panther 10.3.9), holding Option + S while it starts up in single-user mode. Result is black screen with white text; loads of start up stuff that goes by too quickly and the final block of text (about 20 lines of other stuff above it) is as I posted it:
Singleuser boot -- fsck not done
Root device is mounted read-only
If you want to make modifications to files,
run '/sbin/fsck -y' first and then '/sbin/mount -uw /
local host: /root#
It (the start-up software) is telling me that fsck "is not done"; I haven't typed in anything at this stage.
After booting into Single User Mode (as you described), I type the following:
If you use this, it'll modify files where necessary.
Code:
/sbin/fsck -fyIf you use this, it'll modify files where necessary.
Mad Jew said:
Yup. I appreciate that. Thanks. That is what I used to do (/sbin/fsck -y) until I got around to feeling comfortable with UNIX-style commands and actually read all of the words on my start-up screen.
But do you know why I get this warning that the Root device is mounted read-only and if I wanted to modify the files (presumably these modifications would be needed if file errors are found) I have to run the '/sbin/fsck -y' command, followed by the '/sbin/mount -uw /' before running the basic 'fsck -y' routine? I cannot find out if the -uw switch is an instruction to unmount the drive and make it read-write, which is how I have been translating it in my head until now.
On the face of it, modifications to files cannot be made and corrected by just typing in what you suggest? I am waiting until I get some errors and then try to correct them without going through that sub-routine first.
UKnjb said:
I think you forgot the f before the y. It's /sbin/fsck -fy to examine and repair where necessary.
Elan0204 said:edesignuk is a he. His avatar is not him.
People have said in the forums that permisions are repaired "better" if you aren't using the volume that you are repairing permissions on when you do the repair. That is why they recommend the CD method.
However, others have said that since new files are added and permissions might be adjusted by the x.x.x (i.e. X.3.5) updates, repairing permissions without the CD is better, since these changes are not on the original install disc.
Apple Education Support told me that if you repair from the CD, then all of the permissions will be owned by the CD/DVD instead of the HD.
ingenious said:
As long as you're talking about Repair Permissions:
Not "owned" by the CD, there's no such user as "cd".. the permissions in the BOM archives on the CD are woefully out of date in comparison to those in /Library/Receipts/ on your hard drive.
That being said, your comptuer will NOT explode if in a dire emergancy you repair permissions from the CD/DVD Installer. One should simply re-repair permissions at the earliest opportunity when booted from the HD.
It's advisable to always repair permissions from the HD, unless there's something catastrophically wrong.
yellow said:
My apologies... I couldn't think of a better word to use. Your explanation cleared that up for me, though. Thanks!
I accidentally repaired permissions on a Tiger machine from a Panther CD and all was fine. I realised later what I'd done and repaired them again from the boot disk (Tiger) and it made the appropriate corrections. No harm done, as yellow said, but it's not advisable.
