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lawriep
9th July 2010, 11:51 PM
I have a 2 year old iMac 20 inch 2.66GHz upgraded to Snow Leopard OSX.

I have just returned from an 8 week holiday. Prior to leaving I turned everything off at the powerpoint (Modem, Airport Extreme, Printer, Apple TV, External drives etc). The Mac had been running well with no problems prior.

When I returned home a few days ago I could not get the Mac to boot. After turning it on the Apple Logo appears and the small cogged wheel starts spinning underneath. This goes on continuously without booting. Eventually the Apple Logo is replaced by a grey circle crossed with a diagonal bar and the wheel continues spinning.

I turn it all off and after a while try again .. with no success.

Can anyone suggest a way of resolving this?

supafly
10th July 2010, 07:53 AM
Have you tried holding down the option key while it is trying to boot?

ClockWork
10th July 2010, 08:19 AM
The circle with the bar going through it means that your iMac can't find or will not give you access to the Operating System.

The only thing that can be done is to turn it on, insert the Snow Leopard Installer Disc, turn off the power - (by holding the power button down round the back for 7 seconds) - and then restarting the iMac with just the C key held down.

This will force your iMac to start up off the Snow Leopard Disc instead of its own Hard Drive.

It will open up as if it were going to install everything again.
Choose your language, which is English by default, and then utterly ignore the Install OS X window.

Instead, click once on the top menu item: Utilities and scroll down to: Disk Utilities.

In the Disk Utilities window, in the left column - you should see your iMac in the list. Above it, there should be another reference to it, starting with numbers - its capacity in GB - eg: 465 GB WDC WD2500 etc - something like that.

Click once on the one with numbers in its title, to highlight it and then test it by clicking on the bottom-right Verify Disk button.
Let it run through its analysis of your Hard Drive.
If red text appears in or at the end of the analysis, click the Repair Disk button.

Post back your test results.

macuzer
10th July 2010, 09:53 AM
Or try booting into single user mode (hold down apple key and S key as you turn on) if this boots you into the command line, type 'fsck -fy' to run a disc check/repair. once completed type 'reboot' to restart the iMac.

lawriep
10th July 2010, 12:35 PM
Thanks for that ClockWork. I did as you suggested and everything went as you indicated. When the analysis finished after I clicked on Verify Disk, green text appeared telling me
"The volume Macintosh HD appears to be OK"
Wasnt sure what to do next so I closed down and tried to boot again without the Snow Leopard disk in. Problem continued. Would not boot.

lawriep
10th July 2010, 12:42 PM
Thanks Macuzer. Did that. Got to Command Line but cursor hung indefinitely with the message "Still waiting for Root Device"

swoffa
10th July 2010, 06:26 PM
I'm having a similar problem, so I hope OP you don't mind me relaying what's happening to me and what I've tried.

White iMac 24". Have been getting beach balls since upgrading to 10.6.4. with them getting longer and longer in duration. The other night it just didn't cease beach balling so I held the power button down to shut down. From there it just wouldn't boot again. It got stuck on the cog. A couple of times a grey time bar would appear. (You know the sort of bar that would complete as if you copying something). It would only get to about 15% and stay there.

I held the power button down to restart again but got nothing but the cog.
Booted from install disk and ran disk utility. Tried a disk repair but got the message Invalid B-tree node size. Tried a couple of times but nothing. Erased the disk and reinstalled from time machine. Run permission and it repaired pages worth of them. It seemed to OK so I put it to sleep(it was late ).

In the morning I opened Lightroom 3 and then safari.. beach ball again. Nothing but the cog on reboot.
I've now gone back to a 10.6.3 restore and it seems OK but I'm missing stuff I created/saved in the last couple of weeks.
I originally used software update to go to 10.6.4. After restoring from T/M again I was having problems still so I upgraded again using the combo update.
It looks like it could be a 10.6.4 issue?

What could be causing this?

Balthazar
10th July 2010, 07:03 PM
So a little more info...

OP is my dad. (hi dad) and I have done all I can to try to fix this for him already including clockwork and macuzers suggestion (you could have asked first dad :) )

When that didn't work i tried restoring from a time machine backup twice. Both times it appeared to be working but then a day or two later it locks up and on a reset the problem with the grey screen and circle with a cross re-occurs.

I'm thinking there may be something corrupt on the time machine backup but not sure why this waits a few days to present before causing a lockup and not right away after the restore.

Only other possibly related piece of info is that each time after the restore a system window appears asking to find the app "system events.app" which I navigate to in system/library etc...

This one is beyond me. I haven't done a fresh install without a time machine restore, anything think this may work or should we just take to a mac repairer.

glacierdave
10th July 2010, 08:12 PM
At the moment you don't know for sure if you have a hardware or software issue.

That you can check the drive in Disk Utility from the install disc tends to rule out that it's an actual hard drive fault but may still be an issue with controller or some other internal component.

I'd suggest doing a full backup of the internal drive (carbon copy cloner, disk utility, other tool of your choice) and then doing a fresh install on the internal hard drive. If that screws up after a few days you've got a hardware fault of some sort. If it keeps working normally (and a few days seems to be all it'll take to tell you this based on what you've said above) then you've got a software/operating system problem. Finalise your fresh install, restore data from backup and away you go.

macuzer
10th July 2010, 08:47 PM
Found this info today that might relate to your problem. Do you know if you ever had Norton (anti-virus etc.) installed on your iMac, that you later un-installed? Apparently this causes a problem similar to what you have. The info of how to fix this is listed here:
Apple - Support - Discussions - Prohibitory sign at startup, safe boot ... (http://discussions.apple.com/thread.jspa?messageID=11147614)

and from Symantec's site:
Removing Symantec programs for Macintosh by using the RemoveSymantecMacFiles removal utility (http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2007661309063498)

But if you've never had Nortons installed you can try some of the suggestions here:
Mac OS X: "Broken folder" icon, prohibitory sign, or kernel panic when computer starts (http://support.apple.com/kb/TS1892)


and here:
Apple - Support - Discussions - Crossed out circle on start up ... (http://discussions.apple.com/thread.jspa;jsessionid=AD15C09EE533D4BA7A2EFAD3B8E 2B550.node0?messageID=11171680&#11171680)

Interested to see if it boots in 'safe mode' (hold SHIFT key down at startup)
....Hopefully one of these will fix your problem.

swoffa
10th July 2010, 09:31 PM
OK so noob question coming. If I do a clean install of 10.6 and update to 10.6.4 via combo update, How do I get all my data from time machine. I never had to do this before and after 3 years I have stuff all over the place. Is there something that automatically pulls stuff out of timemachine so I don't have to troll through everything?

ClockWork
11th July 2010, 07:43 AM
Answers to restoring from a Time Machine backup plus screen shots here (http://blog.duncandavidson.com/2008/01/restoring-from-time-machine.html).

As to Balthazar, son of Lawriep - I'd suggest either a Fresh Install of OS X Snow Leopard or an Archive & Install (http://support.apple.com/kb/HT1710).

An Archive and Install follows exactly the same path as a Fresh Install, yet during the setup process, one extra option is presented to the User and the end result is that upon restart, everything looks exactly the same as when it was last left and the Macintosh HD contains an extra folder, called: Previous Systems folder - which contains all items, both visible and invisible, from the shonky previous Operating System.

swoffa
11th July 2010, 08:46 AM
[QUOTE=ClockWork;1003245]Answers to restoring from a Time Machine backup plus screen shots here (http://blog.duncandavidson.com/2008/01/restoring-from-time-machine.html).

Cheers ClockWork. This I have already done a couple of times due to what's happened. I now am back to 10.6.3 because that's the most stable restore I have found.
What I was meaning, is how do I get stuff that I've created/changed since the period I restored back to. Mid June in this case. ie our pop mail, downloaded stuff like the 750mb combo update, etc.

I'm also thinking I want to do a fresh install, upgrade to 10.6.4 and see how that goes for a couple of days. If all is well, how do I suck all my data from the latest timemachine which was a couple of days ago.

ClockWork
11th July 2010, 03:18 PM
The finer details of Time Machine and Snow Leopard, I do not know, as I'm not using either. Appy-polly-logies.

But as to Fresh Installations and Archive and Installs, my best advice is to bring up Software Updates, see what it needs and download the .dmg directly from apple (http://support.apple.com/downloads/) - (or search apple's Support to find the correct Updates) and save them all to an external drive in the order that Software Update shows them in, so if any failures ever occur again, one doesn't need to go burning through one's download quota to reinstall them all.

swoffa
11th July 2010, 06:11 PM
cheers CW, thanks anyway.

swoffa
13th July 2010, 09:11 PM
Well I've been through a bit now. I've restored that many times I'm bleary eyed. I found a 10.6.4 which seems to be stable.

What have I found during this exercise.. well time machine doesn't actually back everything up. In fact I now have 90 gig more space than I had before. WTF! I've found out that it won't restore logs, so for me that's no issue as I don't understand them anyway, but I can't help but think they could come in handy to find out why the system buggered up in the first place. I'm reasonably sure I didn't have 80 gig of logs though.

I've noticed one folder that's missing, a particular *ahem* download folder that was residing in the documents folder. No sign of it at all. There was only half a dozen files in there, so at max maybe 10 gig tops. I've recreated the folder, checked it's not one of the excluded within T/M's setting, and it still doesn't get backed up. Anyone answer that one? I would have thought the documents folder would be one of the main folders that would be backed up, isn't that where most people keep their files? Makes me wonder what else it doesn't do. I guess time will tell when I look for something I need.

Did you know you can browse your T/M backups in finder without going through T/M? Well you can.

ClockWork
13th July 2010, 10:06 PM
Might be worthwhile going with SuperDuper! (http://www.versiontracker.com/dyn/moreinfo/macosx/22126) (which I can't link directly to at the mo) or Carbon Copy Cloner (http://www.bombich.com/) for far more reliable methods of backing up your porn absolutely everything on your HDD(s) without missing a beat.

Personally, I use SuperDuper! and know very little of CCC.
With the free or trial version of SuperDuper, one can create a totally bootable backup of an entire machine, without resorting to inserting any installers.

It just creates a fully bootable volume (and can be accurately scheduled to do so in order to keep backing up new or changed files) or activated manually, so when something horrible happens to the internal HDD, it's merely a matter of holding down the option key on restart to select the external volume and everything is just as one left it, ready to be grafted onto a clean HDD.
Believe it's fully compatible with Snow Leopard - any Mac OS above 10.4.

After several incomprehensible bouts with Time Machine, I gave up on it.

It's never too late to give up.

swoffa
13th July 2010, 10:39 PM
haha, I can see your thinking, but none of it was porn.
I've used CCC before and it was very good, but I switched to T/M because of the incremental aspect vs available space. Also from memory I couldn't get multiple copies fo a CCC back up on the same disk. Is it possible to that? Perhaps I'll go off and have a google for that.

swoffa
13th July 2010, 10:54 PM
OK I forgot to check the permission after restoring again, this is about 45 seconds into the verify. Oh Jeez!
http://img.skitch.com/20100713-cpyjcpx51uxb6exxmbcnmdncn2.jpg

Is this line something to worry about? What, to a lay person, does this mean?
http://img.skitch.com/20100713-rfbxt2wya3j2ttjbiq1utk51n7.jpg

ClockWork
13th July 2010, 10:56 PM
I know it can be done with SuperDuper by backing the volume up as sparse disk images, each assigned with a different name and each name can be separately scheduled.

The only set back with this is that although it will indeed copy everything to a disk image, the disk image itself can't be made truly bootable, as it would need to be opened manually by the User.

The other way around this would be to create several partitions on the external HDD and fill each one with a straight-forward bootable backup.

swoffa
13th July 2010, 11:03 PM
The other way around this would be to create several partitions on the external HDD and fill each one with a straight-forward bootable backup.

oooh , I like that thought. I just bought a 1.5 TB drive so i might split that up. Just need an enclosure ;)

ClockWork
13th July 2010, 11:27 PM
I don't think there's anything wrong with the SUID file message in Verify Permissions.
Ever since Leopard was conceived, Disk Utility spits out all kinds of messages like that - not repaired.

If I run a Verify Disk Permissions over my healthy Mac Mini Intel running 10.5.8 now, it comes out with a stream of "not repaired" messages.

~Coxy
14th July 2010, 10:58 AM
I believe that message will appear when you closed off the Remote Desktop security hole at some point in the past (manually set its permissions to not run as root anymore).

Balthazar
14th July 2010, 12:33 PM
So dad took it in for service, upon initial inspection they thought it was a corrupt os, did a fresh install and it failed soon after like each time before.

Their next plan of attack is a new hard drive as they believed the hdd was going, I have my doubts but I'll leave it to the experts.

glacierdave
14th July 2010, 12:47 PM
So dad took it in for service, upon initial inspection they thought it was a corrupt os, did a fresh install and it failed soon after like each time before.

Their next plan of attack is a new hard drive as they believed the hdd was going, I have my doubts but I'll leave it to the experts.

Even the experts have to play the odds.

When installing a new OS works fine it's fair to assume it was a corrupted OS.

When it fails again after a few days, it's then clear the corrupted OS was a symptom rather than the actual problem.

Then it's onto playing the odds again and the next most common thing is a faulty hard drive so replace that, re-install OS and off you go again.

If that doesn't work it means that you're into the realm of less common faults - that might include the controller (motherboard for all practical purposes), the power supply, the cables that connect things together, and so on.

These last lot of faults aren't anywhere near as common in terms of the observed symptoms so they aren't where a repairer goes first when doing a repair.

When a fault can take days to re-occur getting it resolved can obviously take longer. In situations where you can replicate the fault on-demand and straight away diagnosis is far less an issue.

The absolute worst faults are the ones where the tech can't even replicate the fault. Next worst are the ones where it takes days to see the fault happen again.

swoffa
22nd July 2010, 09:24 PM
OK, I think it maybe time for a new internal HD. Nearly everything thing I do causes a lockup. Is there any diagnostic software(preferably a freeby) that actually reports what the problem is with the disk. I recall in my windows days I used to run a prog that would report bad sectors and the like. Disk Utility doesn't really explain jack.

Here's what DU gives me today.

http://img.skitch.com/20100722-m3wuw9p8r7bghwjwjt4afmehak.preview.jpg (http://skitch.com/swoffa/dpstu/disk-utility)
Click for full size (http://skitch.com/swoffa/dpstu/disk-utility) - Uploaded with plasq (http://plasq.com)'s Skitch (http://skitch.com)

swoffa
23rd July 2010, 12:36 PM
bumpity on the post above (hope that's allowed)

ClockWork
23rd July 2010, 12:51 PM
Invalid node structure = borked.

There are no freebies, but if your internal HD is backed up to an external drive, your last resort is to boot it up off the Installer Disc your machine came with, Erase the Drive in Disk Utility, and test it again in Disk Utility's First Aid.

If it comes back with an OK, you can install OS X again, and if it comes up with another red report, it's time to get a new HD.

NB: It's possible that it could be rectified with DiskWarrior 4 (http://www.alsoft.com/Buy/index.html), but that requires payment.

swoffa
23rd July 2010, 02:23 PM
Invalid node structure = borked.

There are no freebies, but if your internal HD is backed up to an external drive, your last resort is to boot it up off the Installer Disc your machine came with, Erase the Drive in Disk Utility, and test it again in Disk Utility's First Aid.

If it comes back with an OK, you can install OS X again, and if it comes up with another red report, it's time to get a new HD.

NB: It's possible that it could be rectified with DiskWarrior 4 (http://www.alsoft.com/Buy/index.html), but that requires payment.

Been all through this many times. Time for another HD then I guess.
The lastest time it happened was when I daisy chained the new external HD. Within a minute of the external being recognised, the song playing through itunes started to pause, followed by a systematic lockup of all open apps.
A hard restart later and the image above of the HD was the result.

CCC to the rescue, I'm now running off the external which has a bootable clone of my internal drive.

ClockWork
23rd July 2010, 03:03 PM
CCC to the rescue, I'm now running off the external which has a bootable clone of my internal drive.

:thumbup:

All is not lost when one has an External Drive.
Swoffa could have been very unhappy.
Note to those who have no External Drives.