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A possible fix for 'overlapped extent allocation' errors System
Recently while running fsck, I ran into numerous "overlapped extent allocation (file xxxxx)" errors. fsck was unable to fix these errors. After reading in several forums that the only way to get rid of these errors is to buy DiskWarrior and rebuild the drive structure, I went to try something else, and succeeded.

I remembered that I had recently force-quit Chimera [robg adds: now called Camino] a few times, and that this could have made my cache files corrupt. I then removed the entire Chimera directory in the Application Support folder of my Library, and checked my drive again.

Voilá, no more unrepairable errors. Of course I remembered the thing with Chimera only after having copied almost all other directories from the drive :-). Does anyone know how to find out which files are affected by taking the xxxxx identifier from the fsck error messages?
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A possible fix for 'overlapped extent allocation' errors
Authored by: karmaworld on Mar 04, '03 10:12:21AM

I too encountered this error and was unable to fix by fsck. I came across a post in Apple discussions where someone suggested running OS9 disc repair utility. Since I have been "classic free" for some time now, I booted up from my OS 9.2.2 cd, ran Disc repair from the CD and voila, problem solved with no ill effects on my G4 933. It has been about a month now.

---
With kindest regards,
Laurence



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A possible fix for 'overlapped extent allocation' errors
Authored by: revcosmo on Mar 04, '03 03:18:22PM

To become "classic free" did you simply delete the OS 9 System Folder, or was there more to it than that?



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A possible fix for 'overlapped extent allocation' errors
Authored by: tlassiter on Mar 04, '03 05:53:10PM

I have experienced this problem at least a half-dozen times since June
2002 with a PowerBook G3/400. At first I blamed flakey RAM and
replaced it with guaranteed RAM. A larger (and needed) hard drive made
no difference. Neither did upgrading to Jaguar 10.2.3. Last week I had
another occurrence that Disk Warrior could not repair. fsck kept finding
overlapped files. Rather than wipe the drive (again), I reinstalled the OS
with the Archive and Save option. Other than having to reset everything
and losing my User file and docs, the PowerBook seems OK again. But I
don't trust it with critical files.

If this problem were to occur with the desktop system that pays my bills,
I would be sunk. Until OS X learns to behave, I can't trust it and won't
convert the machines that I depend on for my livelihood.



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A possible fix for 'overlapped extent allocation' errors
Authored by: osx_4me on Mar 05, '03 11:32:59AM

I have used 10.2 on numerous machines, without ever having any 'overlapped extent allocation' errors. And I use fsck more often than I really need to.
I'm sorry you're having problems, but it's wrong to blame this on OS X. Sorry.



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It is more likely an HFS/HFS+ file system bug
Authored by: jollyroger on Apr 04, '03 08:10:09AM

If your hard drive ever reached the point of being over 85%-90% full, then it is likely that the HFS file system caused the extents tree to be overwritten (overlapped) because the B-Tree portion of the directory itself was out of space!

Take a look at the comments in this MacFixit forum:

<http://www.macfixitforums.com/php/showflat.php?Cat=&Board=Forum8&Number=435249&Forum=All_Forums&Words=&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=1day&Main=435138&Search=true>

Pay attention to MacWizard's comments (he is/was on the TechTool team). Some quotes:

" HFS+ does a much better job of keeping track of files that have many pieces (extents). If an HFS disk is heavily fragmented and more than 70% full, irreparable damage can take place to the Extents B-Tree portion of the disk directory if any more files are added. The corresponding limit for HFS+ disks is 85%."

and

"If the disk is more than 85% full, and is sufficiently fragmented (something I cannot precisely define), the Extents B-Tree is in danger of irreparable damage. When new entries need to be written in the Extents B-Tree, older ones are simply overwritten. The developer of TechTool Pro has reproduced this problem in a lab setting.

The Extents B-Tree keeps track of file extents (pieces) beyond the first three extents of each file (those are recorded in the Catalog B-Tree.) Within Apple, the Extents B-Tree is called the Extents Overflow file. The name alone suggests a potential problem. I suggest you archive some of the data as soon as possible.

I have screenshots of disks that have zero free bytes and still work, but they were not heavily fragmented. "

I'm not sure I can remember where or when, but at some point, years ago, I learned that you should never fill a Mac HD more than 90% or you will have problems. Since then I have only let my hard drives get 90% full on occasion. And I do seem to have much fewer directory-related hard drive problems than other Mac users.



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A possible fix for 'overlapped extent allocation' errors
Authored by: kioneo on Mar 04, '03 10:15:15AM

This has happened to me before as well.

Just use:

find / -inum xxxx

This will find the file with the inode number xxxx by searching your entire drive starting at the root. Just make sure you run it as root otherwise you will get permissions errors as it traverses directories.

Once you find the file, decide if it is safe to delete and do so. Then fsck again, and you should be fine.

---
If you can't be promiscuous, what's the point [of sniffing]?



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A possible fix for 'overlapped extent allocation' errors
Authored by: Carbonide on Mar 05, '03 03:49:31AM

Thanks, great hint! I'm currently trying to figure out what files are corrupt and delete them using the terminal. But as there are a few hundredof them this will take forever.

Shouldn't it be possible to write a shell script that goes through a text file with the node numbers, retrieves the file name and moves it to a certain directory?

Any shell guru out there?



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A possible fix for 'overlapped extent allocation' errors
Authored by: sbwoodside on Mar 05, '03 01:01:47PM

Don't do that. Before you move/remove any random system files you should know what they do and whether or not removing them will hose your system.

simon



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A possible fix for 'overlapped extent allocation' errors
Authored by: Carbonide on Mar 06, '03 04:34:01AM

How about only moving files that reside in the Applications folder? This would probably get rid of most of the errors as System files are the first installed on a disc and tend not to change that often than those the user installs, so they aren't as susceptible to become implicated in extents overlap, are they?



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A possible fix for 'overlapped extent allocation' errors
Authored by: dashard on Apr 04, '03 09:27:17PM

How about a shell script to list the 'inum' followed by the path to what was found and put it in a text file at ~/Desktop. This way one could see what was what and then determine the best course of action without having to slog through the error numbers one at a time??

Anyone??



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A possible fix for 'overlapped extent allocation' errors
Authored by: webmonster on Dec 10, '03 07:00:58PM
This is UNTESTED, so USE AT YOUR OWN RISK (in other words, it may require minor tweaking, but it's at least some starting point - it is not elegant at all)

for num in `fsck -n / 2>&1 | grep "Overlapped extent allocation" | cut -d'(' -f2 | cut -d' ' -f2 | cut -d'd' -f1 ` ; do find / -inum $num ; done > /OverlappedExtentAllocations.txt

This should produce a file in your boot volume's root directory.

I had the overlapped extent problem right now, but I cured it quick because I moved several files to a different disk before running fsck, so I didn't really try the script above.

Maybe it helps.

Regards, /k

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A possible fix for 'overlapped extent allocation' errors
Authored by: johnsawyercjs on Dec 11, '03 02:25:43AM

Diskwarrior will list overlapped files by name, as long as it doesn't choke on the diagnosis phase. Use version 3, it's much faster than version 2, and boot from the Diskwarrior 3 CD, since DW 3 doesn't work yet under OS 10.3.x.



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A possible fix for 'overlapped extent allocation' errors
Authored by: ivarv on Nov 15, '03 11:32:39AM

Thanks for the tip. I had one of those and wanted to fix it before the Panther. I logged in as root and ran the command, at first it gave me something with trailing error caracter, but I tried again and suddenly it gave me the file. It was an iDVD file. I just started to use iDVD last month and only tried a lttle bit. Deleted my test project and verified the disk. I was clean. Thanks for the tip.



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A possible fix for 'overlapped extent allocation' errors
Authored by: jceaser on May 01, '05 04:22:44PM

Great tip, saved me from reformating my drive. Wish this site had mod points.



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A possible fix for 'overlapped extent allocation' errors
Authored by: sumnchai on Mar 04, '03 11:30:28AM

i'm kinda mad...long story short, i had an OEA and when i called apple, they said that the only way to fix it was to wipe the hard drive and reinstall OS X - and this was from an senior tech. if this works, consider my faith in the apple tech help severely damaged.



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A possible fix for 'overlapped extent allocation' errors
Authored by: terceiro on Mar 04, '03 11:38:51AM

If it works, I'm mad too. I just had to go through that whole rigamarole -- neither Disk First Aid (on the OS X disks) nor Drive10 couldn't repair it. I wiped and reinstalled -- and spent two full days doing it. Sigh.

Next time I'll know.



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A possible fix for 'overlapped extent allocation' errors
Authored by: ahknight on Mar 04, '03 12:04:57PM

I don't see why you'd get mad at them. They're not there to go kernel-hacking for you, just explain how to get iTunes to stream. Technical support is granny-support, not power-user support. Power-user support is called "consulting." :)



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A possible fix for 'overlapped extent allocation' errors
Authored by: osx_4me on Mar 05, '03 11:39:47AM

AMEN !

This is true for the first-line support at any computer company, folks.

That's what we're here for. If the posted fix works, submit it to Apple at http://www.apple.com/macosx/feedback/
They just might post it as a knowledgebase article. For the record, any command-line level fixes are very likely going to be outside the realm of knowledge for any first-line support folks at Apple, and we should probably suspect that those folks are in fact told to NOT stear Granny (or any other caller) in that direction.



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A possible fix for 'overlapped extent allocation' errors
Authored by: saint.duo on Mar 04, '03 12:40:08PM

It won't always work. Sometimes those overlapped files are core system files. The best overall fix is to nuke and reinstall.

---
--
duo



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A possible fix for 'overlapped extent allocation' errors
Authored by: smkolins on Mar 04, '03 01:44:49PM

I agree. There is actually nothing new here. If you happen to know or figure out what's crosslinked you could always delete just those parts and ussually recover pretty gracefully. Figuring out what's crosslinked may be hard. In this case he just guessed and guessed correctly.

This just underscores one thing about the OSX force quit process. Yes the ram/active OS may be ok, but no there's no gaurantee the hd is.

---
= - - -- - - - =
Steven
smkolins@mac.com
http://homepage.mac.com/smkolins
Possess a pure, kindly, and radiant heart!



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A possible fix for 'overlapped extent allocation' errors
Authored by: Gus on Mar 04, '03 03:45:06PM
Would turning on journaling help Disk Utility and/or fsck in fixing these problems? Just a thought ;)

---
--
Ing. lic. G.E.A. Vansteelant
Lead Assessor

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A possible fix for 'overlapped extent allocation' errors
Authored by: smkolins on Mar 05, '03 08:26:29AM

Interesting thought....

I'ld like to see some experiments.

However until then... my thoughts are... that it would still crosslink. Journaling does check the sanity of the requests for allocation as far as I know. It just checks that they were accomplished. Still I suppose it's possible journaling would read the incoming requests as undelivered and not execute them, or delivered, find them unfinished, and execute them correctly at boot.

Definately need to test this!

---
= - - -- - - - =
Steven
smkolins@mac.com
http://homepage.mac.com/smkolins
Possess a pure, kindly, and radiant heart!



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A possible fix for 'overlapped extent allocation' errors
Authored by: tanvach on Mar 05, '03 04:41:13PM

I have had my harddisk journaled since 10.2.3, but the number of the overlapped extents had gone up since then. There used to be about 4, now there are 10!

Tan



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A possible fix for 'overlapped extent allocation' errors
Authored by: lamon on Mar 05, '03 05:20:56AM

From what I know, HFS+ is fragile when the disk is filling up too much. You do not risk this problem unless you go over 85% occupation of the disk (note that UFS on Unix usually reserve 10%). The main cause I have seen for this is usually the swap file growing up and filling the partition (could also be a runnaway log) and a lot of other problems are due to this, like corrupted or diseappearing preference files.

So the best idea is to create a separate partition for swap files, and maybe log files also if you are running a server. I have that set-up and never had a problem in 18 months of use of OSX.

If the problem happens, you have two files referencing the same extend. The problem is that you do not know to which file the data in the extend belongs to. If the overlapping files are user file, you can copy them, delete both originals and you should be OK. If the overlapping files are system files, you may disrupt the system and be unable to reboot by removing them. In that case, I would boot on another disk or a bootable system CD, surgically remove these files and create a new copy from the working drive or CD. Otherwise, reinstall.



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A possible fix for 'overlapped extent allocation' errors
Authored by: smkolins on Mar 05, '03 08:29:08AM

I agree about the problems of filing the hd, and while it could be because of the swap file(s) I think it's more likely that the system will go nuts trying to find unfragmented space (or actually give up) and fragmentation on the most recent files will go through the roof.

See man tunefs.

---
= - - -- - - - =
Steven
smkolins@mac.com
http://homepage.mac.com/smkolins
Possess a pure, kindly, and radiant heart!



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A possible fix for 'overlapped extent allocation' errors
Authored by: lamon on Mar 05, '03 08:45:43AM

True. But usually, the system fails to find space because the HD is full, and I think that one of the main causes of accidental fill-up is a runaway swap. If you keep 85% free, you should have no problem. I have been up to 95% on an archive partition (large files only) without problems either.

I can't check here at work but is tunefs relevant to HFS+? I throught it to be a FreeBSD/UFS manpage.



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A possible fix for 'overlapped extent allocation' errors
Authored by: smkolins on Mar 06, '03 10:16:06PM

Perhaps. I'm seeing lot's of references to bunches of OSes - linux, BSD, HPAUX... I'm seeing references to hfs modifications....

Nothing direct yet, but I know the command iostat wasn't enabled correctly in 10.0 or 10.1 but it works in 10.2....

tunefs might be there but not exactly reachable....

---
= - - -- - - - =
Steven
smkolins@mac.com
http://homepage.mac.com/smkolins
Possess a pure, kindly, and radiant heart!



[ Reply to This | # ]
A possible fix for 'overlapped extent allocation' errors
Authored by: sidharthamacdoc on Apr 16, '03 05:54:28AM

I suffered the dreaded OEA error when my HD was only
20% full! Contrary to most of the threads of the error
occuring when the HD is over 80% full.

Makes me kinda weary whenever I install apps or if the app
generates cache files.

As I am new to OSX, how do you move swap files to another
partition? I know how to do this in Netscape and
Photoshop, but the others, like Safari etc?



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A possible fix for 'overlapped extent allocation' errors
Authored by: Anonymous on Mar 04, '03 12:51:17PM
Use the 9 CD to boot, run disk warrior 2.1 something (ran it from the disk I was fixing, other partition though).

Wait, wait wait...
(about 16 hours on my original iBook with a 20 Gb HD).

Fixed!

Happy! ( $69 poorer too)



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A possible fix for 'overlapped extent allocation' errors
Authored by: Carbonide on Mar 04, '03 04:54:06PM

I did a post on MacFixit 2 days ago because I'm having the exact same problem even with journaling turned on on my PowerBook G4 since I received it 3 months ago (running 10.2.4 currently).

I *never* had to force quit any app, experienced no kernel panic and had only very few crashes of apps (about a handful I can remember).

Yet, despite of this stable set-up I have more than 400 overlapping files!! How's this possible?

A first run of DiskWarrior repaired some errors that could be fixed, but it failed to repair (move?) the overlapping files as the last step. So I tried Disc Utility but that didn't help either.

When trying to run DW a second time (as it suggested) I stopped it after about 10 hours as I thought it stalled. I've now started it again as someone suggested it can take over 16 hours. Is there a sure way to tell if it's still doing its job or just stalling (ProcessMonitor, top etc...)?

BTW, I checked for disc errors because when logging in under my normal user account, the dock restarts repeatedly and the Finder won't get loaded. Other users (including root) work just fine. Deleting prefs didn't help. Any other idea?



[ Reply to This | # ]
Just a thought....
Authored by: SJT on Mar 04, '03 08:12:31PM

I've never had this problem at all; and I've had to force quit lots of apps at some point or other, or something has crashed.

However, I keep my machine on permanently so it has a chance to run the cleanup jobs nightly, weekly and monthly.
Seeing as a few of you seem to be laptop users, you probably don't do this...so maybe you should move the cron jobs under the root user's tab to something like anacron or at, or reschedule the jobs so they are actually run when the machine is on. Maybe this will ensure that inodes don't get cross matched?
(to be honest, I don't actually know what the cron tasks do...so I'm sort of guessing here)



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Just a thought....
Authored by: noblee on Mar 04, '03 11:32:42PM

No, the cron tasks will not help here. The errors they are finding are pretty naughty errors in the CONTENT of the files. the cron tasks are mostly dealing with daemons; the cron tasks do not affect the basic file structure. If you are curious, check out:

/usr/sbin/periodic
/etc/defaults/periodic.conf
and the files they direct you to.

That being said, it is never a bad idea to run these scripts.

The concern I have is that I just checked--not a single file error on my PowerBook G4 that has been running now for a little over a year. I am also a pretty hard user on my poor box.

What did these users do that caused this? On my old Linux box, this was not too uncommon, but I was very impressed with OS X for having no file errors on this box until I heard about their stories.

I can see how force quitting could cause this, but I force quit Office apps daily and I kill Fire every few days and Safari once a week. And yet, I have no such corruptions. I would like to see what they all do similarly.

Oh, and I am really not at all sure that this is an OS X issue. I blame it on a cludgy app or apps, or at least I will blame it on non-Apple software until someone shows me an Apple link. Generally, Apple software is better than non-Apple software (even if Apple software is sometimes horribly broken itself!)



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How to dodge an OEA reformat bullet?
Authored by: 1e6 on Mar 06, '03 02:51:39AM

Superstition or lucky guess? I don't know, but when my TiBook's "overlapping extent" problem was not fixed by fsck, I too got ready to reformat my HD... except first I happened to notice a corrupted font, so I replaced that with a good copy from backup (yea!) and then I ran MacJanitor to do UNIX housekeeping tasks... and, whaddaya know... voilá: problem gone!



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A possible fix for 'overlapped extent allocation' errors
Authored by: miggins on Mar 04, '03 10:18:57PM

Only a few days ago I had this same problem, combined with the dreaded 'keys out of order' problem.

fsck, DiskFirst Aid (from OS X and OS 9) which are really the same thing could do nothing with it - not in single user mode or anything. I ran these perhaps 20 or 30 times.

Then I started from my OS 9 volume, ran DiskWarrior 2.1.1 and an hour or so later (2.5 gig volume) it rebuilt the drive directory.

No problems now.



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A possible fix for 'overlapped extent allocation' errors
Authored by: MicFlash on Mar 05, '03 01:34:04AM

Hi everyone.

I also had the same problem about a month ago on my Dual 1.25gHz running 10.2.3 (before the 10.2.4 debut). I woke my computer up from sleep, and it was in single-user mode with a bunch of random garbage on the screen. I used the reboot now command to restart, and the restart took over 5 minutes. Once I managed to login, which was another 15 min of waiting, I ran Disk Utility and found numerous OEA errors. All the usual fix-it's didn't work, and I called Apple Tech Support. He suggested I do a full backup and reformat of my main drive. So much for tech support. Still the only thing that cleared up the problem, everything is running smooth now on 10.2.4.



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A possible fix for 'overlapped extent allocation' errors
Authored by: everydave on Mar 05, '03 09:55:42AM

I had a G4 DP 867 with the overlapped extent allocation error, and after reading about the DiskWarrior fix I downloaded it and gave it a try by hooking a G4 laptop up to the tower via Firewire Target Disk Mode, as this was the only way the HD could be recognized. I let DW run, and, two days later, it was at 4400 files found, but no fix. Having had enough of that, I ran Tech Tool Pro from the laptop, and about an hour later, it had fixed it. Something of note, when running the individual fix for volume structure, it was taking a very long time, but when I ran Tech Tool Pro in the "Auto" mode that checks everything, it zipped right throught the problem.



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a possible culprit
Authored by: lugal on Mar 05, '03 11:04:57AM

I support over 400 Macs at a school. I usually get about one person a month come to me with this problem. For me, DiskWarrior always repairs the directory, but sometimes I still have to replace the damaged files with intact ones. In every case (under OS 9), the culprit is LimeWire. No lie: the cross-linked files are ALWAYS LimeWire downloads. So far, I've only seen this problem twice on OS X machines, but one case it was with LimeWire downloads, and once (on my own computer, no less) it was in Acquisition downloads. Now I'm very leery of these Gnutella clients--though perhaps the problem is with Apple's JVM.

Regardless of the source of the problem, though, I find that the longer it goes unrepaired the worse the damage to the drive becomes, eventually rendering the computer unbootable from its hard drive (though still repairable by DiskWarrior).



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a possible culprit
Authored by: lugal on Mar 06, '03 01:00:45PM

Ok, so I must've pissed off the computer gods with my previous post. Last night, I had a kernel panic. Booted back up in single user mode, ran fsck, and found dozens of files with overlapped extensions and a couple multi-linked files. Using the advice on this thread, I found that they were all Chimera cache files. Deleted them, re-ran fsck, and am humming along happily again. So add my old copy of Chimera (2002122004) to the list of programs that don't clean up nicely after themselves. (Any sense in upgrading to a newer version of Chimera/Camino?)



[ Reply to This | # ]
Limewire
Authored by: WG Sea on Jul 14, '05 04:34:09PM

After 4 days I finally found someone that noted Limewire as being the problem.
I have tried the following repairs:
Disk Warrior found 2 Overlapped Extent Allocation Files but could not fix, ran several times.
First Aid continues to fix the HFS Volume, however I can never a get clean repair.
Target Disk Mode via Firewire does not mount HD on the host computer, however it is visable using Disk Warrior and Tech Tool Pro
I am using a iBook G3 running OS X

I would be very interested in learning how you resolved the issues of fixing the Overlapped Extent Files.

Thank you in advance,

WG Sea



[ Reply to This | # ]
A possible fix for 'overlapped extent allocation' errors
Authored by: DavidRavenMoon on Mar 05, '03 09:51:46PM

It's the cache files that cause the problem. Whenever I have to force quit Mozila or Chimera, I manually trash the cache files.



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A possible fix for 'overlapped extent allocation' errors
Authored by: ankh on Mar 06, '03 12:20:15AM

Pismo 400, OSX 10.2.4, and this happened to me last Friday, after one of those "gray screen saying you need to reboot in many languages events" I've gotten used to them, since AppleCare says they have never found a hardware problem with my Pismo. Some people just have bad luck.

Disk Utility this time found 9 overlapped extent allocations -- listed one number four times, then five other numbers, said it had fixed it, but hadn't. Tech Tool Pro couldn't fix it and said to recover files and reformat. Drive 10 has always just crashed my computer when I restart after using it and never worked. Disk First Aid claimed to have fixed it but failed. Disk Warrior claimed to have fixed it but hung during verification. DW support said rename the Users folder as aaUsers and see if it hangs earlier -- it did.

Threw out all the caches and that did not help. Tried all the above again and that did not help -- it's not always the cache.

DW support said DW may die if it hits a non-ASCII first letter in a filename. I found I had a lot of files, system files, with a blank space as the first name (huh?). Deleted the system from the drive. Still hung. Bought a spare hard drive.

Oh, did I mention that when I went to my mirror backup external drive, it also had the exact same overlapping extent allocation files? And I had run the disk utility == always do -- after I used TriBackup to mirror the main drive, and it had been fine the night before. Creepy.

So I bought another drive at Computerware at 5pm Sunday, copied everything with TriBackup.

Deleted the user files, still hung. Reformatted, wrote zeros, and am reinstalling.

Apple doesn't recommend or support Tech Tool even though they distribute it, and apparently claims nobody needs a disk utility with OSX.

It's always nice to talk to Apple about these problems. Such a nice world their tech support people must live in. They never have heard of such problems happening to anyone else. Oh, and firewire ports never fail, hinges never crack, and screens don't turn pink. If they were telling investors this kind of lie in securities deals the SEC would close'em down, but since they're telling customers it's considered puffery, legally not a problem.

"If you can't make it good, make it look good." --- William Gates, 1995

Reformatted. Reinstalled. Gonna do it on the other two drives as well.



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Journalling hides them!
Authored by: owain_vaughan on Mar 06, '03 08:27:29AM

With jornalling on you just don't get to see fsck reporting the OEA errors. I just got a load of them after installing the latest security update. They must be in /System/Library/Frameworks somwhere, because after messing around with gdb in single-user mode I managed to get Window Server to work by copying dylibs from another box, but loginwindow.app? No dice. Turning off journalling allowed fsck to run properly on reboot and admit that there were OEAs everywhere. Oh well. Crossover cable all the data and apps away and re-install :)



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OS 9 + Norton 6 usually works...
Authored by: heavyboots on Mar 06, '03 08:11:25PM

Yes, it's a lame thang, but I've fixed this sort of thing successfully with Norton. I think this is the one where you end up with a lovely folder of alias's to possibly damaged files.

For entertainment value, however, my boss recently lost his entire Workspace partition during a brownout, as it crosslinked his directory somehow. OS X, in its infinite wisdom, noticed the missing volume at reboot, realized the Home folder was supposed to be there and so helpfully created a very small "pretend" volume with default prefs for a fresh user. Now that scared the hell out of him! And the capper was that since this is an MDD G4 Apple didn't bother to include an OS 9 boot disk, so I spent about an hour and a half scavenging the OS 9 disk image off the OS X install CD, stuffing various disk utilities on it and burning the whole thing with Toast as a bootable OS 9 disk that could see the lovely new ATA133 bus (old 9.2.2 disks just don't even mount the drives off that bus, which is also scary for any audience members).

Once I got all that pieced together though, Norton blazed through and fixed it first try. I think I earned my bonus for the year. :-)

wheeee...



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A possible fix for 'overlapped extent allocation' errors
Authored by: tjamison on Apr 28, '03 06:03:17PM

I have been having this problem with a G3 Imac and thought I
was alone. I had the problem, reinstalled OSX and things
seemed fine, then all of a sudden stuff stopped working (many
apps) and progressively got worse until finder wouldn't start. I
went to the OSX install disk and ran disk utility, only to find
hundreds of OEA errors. Decided to wipe the volume clean. Did
an Erase (using the Erase tab) and reran repair on the erased
volume 3 times in a row. 1st time got a minor error - repaired.
2nd time it looked clean. 3rd time got 1 OEA error. What's
going on here?



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A possible fix for 'overlapped extent allocation' errors
Authored by: heynnema on Apr 28, '03 08:13:19PM

I have the same kinds of errors. Nothing I could do would get rid of
them. I got used to booting into single user mode and running fsck all
the time...

then I disabled all of the Symantec/Norton startupitems and extensions,
and guess what?!? ALL OF THESE EXTENT ERRORS WERE GONE, AND
I'VE NEVER SEEN THEM AGAIN!!!!

AND... my USB floppy disk drive no longer complains when I try to eject
a floppy disk with a "this disk is in use" error message. It now ejects the
FIRST time, without error, instead of always requiring TWO eject
commands to make it happen!!!

Symantec/Norton stuff has ALWAYS been bad news, even in OS 9!



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A possible fix for 'overlapped extent allocation' errors
Authored by: TI bookuser on May 18, '03 12:53:23AM

I have a TI book G-4 867 running 10.2.6. The finder would not reboot ("blue screen of death"?) last evening. Apple Disk Utility on the Jaguar system disk showed MountCheck reports serious problems and 4 OEAs that it couldn't repair. Tried the Disk Repair on OS9 disk, that didn't work either. Disk Warrior 3.0 on a BootCD 0.5.3 emergency CD claimed to repair 2 OEAs. But Disk Warrior Preview of the hard drive showed all of my desktop files gone! Sweated profusely after choosing to accept the modified directory in Disk Warrior. Was ready to give up, and then decided to try Archive and Install option on 10.2 Jaguar system disk. Brought the Finder back, including the desktop files! Lesson may be to start with Archive and Install Jaguar off the installer disk, then worry about the OEAs later when you get your Finder back.



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A possible fix for 'overlapped extent allocation' errors
Authored by: ckgaparajita on Sep 08, '03 06:54:27PM

I just killed a bunch of them, most of them were in the Safari favicons cache.



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A possible fix for 'overlapped extent allocation' errors
Authored by: johnsawyercjs on Dec 11, '03 03:02:25AM

And here's my hard drive directory damage story...

I think it's possible that booting back into OS 9, with large (greater than approximately 25 gigabyte) volumes containing hundreds of thousands of files, even when they're HFS Plus/Mac OS Extended volumes, may sometimes damage the directory on those volumes, since OS 9 may be less "robust" at handling large volumes with lots of files; that, plus excess fragmentation may have played a part, as described in some posts above. About a year or so ago, when I was using drives smaller than 40 gig on a beige desktop G3, exclusively under OS 9, I had occasional directory damage, but nothing like the frequency I began to see when I started using 40 gig and larger drives, initialized as a single volume. When I started using 40 gig and larger drives, again under OS 9, I began to see directory damage occur more frequently, several times over the past year. After my 40 gig crashed bad, and wouldn't appear on the desktop, I recovered its files onto a 60 gig, leaving about 20 gig of free space for a while. It ran fine under OS 9 for several months, then as I began to fill it up, it crashed too, with significant directory damage, causing it to appear on the desktop only occasionally, so I recovered its files onto an 80 gig drive, partitioned as a single volume, which I used under OS 9 for about a month, after which I replaced the beige G3 with a Blue&White G3 so I could run Panther. After I installed Panther onto the 80 gig, I was in the habit of booting back and forth between OS X and OS 9, depending on what I needed to do. Within a few weeks, the 80 gig's directory was damaged and needed recovery. I began to wonder if the increasing volume size might be one factor, and wondered what would happen if I partitioned my drive into smaller volumes. I hadn't seen the directories on my earlier, smaller drives (10 and 20 gig) get damaged so quickly, running under OS 9, so I decided to see how 25 gig volumes would fare. I used Disk Utility from OS 10.3 to initialize my 80 gig drive into three equally-sized 24 gig volumes, then I copied my files to them, leaving at least 8 gig free on each, and now I've booted into 9 several times since, and have checked the directories on the 24 gig volumes several times, and none of them has had any directory damage after booting into OS 9 and then back into OS X. So the lesson may be: If you use volumes larger than about 25 gig, don't boot back into OS 9 if you can avoid it, and if you do, stay in OS 9 for as short a time as possible; if this isn't practical, partition your drives into volumes no larger than 25 gig. I know a lot of people will find that they've gotten along fine with volumes larger than 25 gig, even though they boot back into OS 9 frequently, but that's the old YMMV (Your Mileage May Vary) phenomenon.



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A possible fix for 'overlapped extent allocation' errors
Authored by: logray on Mar 17, '04 07:34:46PM

before i update the system with an new version (this time wanting to install 10.3.3 from 10.3.2) i boot from the DVD that came with mac (g5-2x2) and run disk utility. this time it came up with 5 files that had "overlapped extent allocation" errors and it listed a number after it. i typed in the numbers using "find / -inum xxxx" in root/terminal and it came up with the locations. i deleted one that was just a normal file that i had a clean backup of but the other ones were in a "lost+found" folder. here they are:

/lost+found/1502096/httpd.pid
/lost+found/1502096/named.pid
/lost+found/1554557/netinfo_local.pid
/lost+found/1686875/syslog.pid

any idea what the folder is, what these files are (pid?) and if they can be safely deleted.

thanks in advance.
btw, fsck or running disk utility does not fix these errors. and not sure as this mac does not boot 9 if doing target disk mode from a pb in 9 would work and then running disk utility...



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got same errors but on non-OS external drive
Authored by: david babel on Nov 04, '05 09:54:09PM

I am getting this overlap error when i try to mount an external firewire onto my new mac mini - a drive that has no problems bein g used by my powerbook still running OS9.2. That is to say there is no OS on the problem disk, but Disk Utility can't fix it and mount the drive. Suggestions?

thanks

David



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