Disk Utility vs Disk Warrior - Doesn't make any sense
I'm totally baffled to figure out what's going on and what the best next step would be.
In a nutshell:
I'm running 10.4.11 on an external McAlly FW drive that was CC clone from the internal maybe two weeks ago.
Made a CC incremental clone from the McAlly drive to the original internal over night with the intention to boot up on the internal this morning and use it instead of the external.
Clone complete fine.
I try to elect the internal by holding down the option key on tart up - it doen't how up a a boot option. I only get the external and two other that I had cloned month back.
So I start on the external again, elect the internal I just cloned to in the System Preference menu and boot up again.
Now the Mac tries to boot up on OS 9 with a message that on OS 9 one can only boot up from the original disk.
So even though the internal shows up as a boot drive with 10.4.11 in system preferences, the system doesn't see to see it.
Tried a second time, same result.
OK - I decide to fix the internal drive I'm trying to boot on.
I now boot up on one of the older clones from several month ago with the intent to repair the internal that I cloned to and want to boot up on.
Run permissions - repairs a few minor things
Run Mac disk utilities - comes back with a minor error which was corrected and the drive gets a clean bill of health.
I then decide to run Disk Warrior on that same drive that Disk Utility says its fine and I get this message:
Disk Warrior has successfully built a new directory for the disk named (my internal disk name displayed. The new directory cannot replace the original directory because the original directory was too severely damaged.
What the heck????
First of all I thought the whole purpose of Disk Warrios was to rebuild and replace damaged directories - now DW tells me it can't fulfil it's main purpose as a retail tool
And second - how can disk utilities end up giving this disk a clean bill of healt and DW says it's so badly damaged, DW can't even fix it.
And remember - this is a CC clone I made over night from a perfectly fine running external
All this somehow doesn't tie together.
Now - in detailed DW messages under Folder it mentioned that it did bless this sytem folder, so that would explain why that dik couldn't boot up - somehow an issue with the CC clone.
The other detailed messages were:
Repaired the root creation date
Repaired Folder Flags
Repaired Text Encoding (in six different locations)
That's it.
Any insight what the issue might be -= especially why does disk utility think the drive is fine and DW thinks it's beyond repair?
Just ran disk utility again just to make doubly sure.
Still comes up clean
Tried the start up with the option key again.
The internal drive still doesn't show up as a boot drive.
What about reinstalling 10.4 to that problem drive?
I'm beginning to wonder if the CC incremental back up has an inherent problem.
I had an issue with that once before.
So either do a complete erase and back up or use Super Duper.
Any recommendations?
I used to use SD until they lagged behind in something, then used CC for a while with no problems until recently.
Could be a CC problem - I have only used SuperDuper since CC lagged behind SD!
I have found Disk Utility will sometimes say everything is ok when it's not. I've experienced a dying drive which DU repeatedly "fixed" - but which eventually died. Disk Warrior was more accurate in pinpointing the problems in that case, which were, in the end, insurmountable.
If your external drive is fine and you'll not lose anything on the internal drive, I'd just erase and reinstall OS 10.4. Then, if all is well, use Migration Assistant to move over the things you need from the external drive.
I'd be a little hesitant to simply clone the external back to the internal again, as this was what caused the problems to begin with. (Of course, depends on how much time you want to spend on this too!)
You could also try running DW again and seeing if it will replace the directory after the second repair. There is a point where the directory damage cannot be repaired and you do have to reformat and reinstall - that's why we have DW AND backups!
Internal drives are fairly new, less than six month old.
These are 1.5 TB green WD's in a G4 tower and I use one partition on them for storage of large files - they seem to be OK.
I think it's obvious something went wrong with the incremental CC clone but why would DW not be able to REPLACE the directory it apparently has successfully created?
I thought that's the basic function on DW - go through all the files and folders on the disk, create a directory for those and then delete the existing directory (which may be corrupt) and replace it with the newly created one.
Why would DW require the existing directory to be not too corrupt to replace it - anyway, that's what the message tells me.
I think I'll try a complete clone (not incremental) tonight using CC but to a different hard drive...or would SD be better at this time?
And it is possible that you in fact have a defective drive. The only way you'll know for sure is to erase and reinstall and as I noted - I'd try the clean install route which leaves absolutely no doubt about whether or not a clone is causing the trouble you're seeing. If that works, you can always clone it afterwards. You want to be sure that the drive can actually be trusted going forward.
Disk Utility and Disk Warrior perform different functions; one is not a replacement for the other, nor would I expect them to find the same issues.
It's not unusual in my experience to find Disk Warrior will find small errors on even a lightly used recently formatted disk, and suggest a repair.
If DW cannot replace the directory, that does suggest some low-level issue.
If the DW error is a result of bad sectors (areas of the disk that are not able to accept data properly) and in my mind DW's inability to replace the directory suggests a bad sector has developed where the directory lies, then the way to have OSX map out those sectors is to do a "zero all data" in Disk Utility before you reformat which will read each sector and if bad, map it out (tell the OS not to write there anymore).
Sectors go bad all the time; most hard drives have areas that are mapped out from the factory, and include other areas that are "saved" and are used to replace those sectors.
However, it's also a sign of a failing disk if bad sectors start developing in areas that were previously good. Monitoring of how many sectors go bad over time is a fundamental method of determining if a disk is becoming unreliable. With external drives, you normally don't have the advantage of SMART reporting to warn you of imminent failure.
It's also possible this is a problem with CCC, which does not always produce perfect clones in my experience. However, I haven't played with CCC in quite a while, as I decided to use other tools to back up with. It's possible it's more robust now; and blameless. It's worth looking into, however, if you intend to continue using CCC.
It might be that in cloning from/to the three drives you have inadvertently copied the problem to the others ... i"m not exactly clear on what you have done so far. But, a bit-for-bit copy, which a true clone should be, could certainly do that.
I would suggest running your utilities on all three drives (two externals and one internal) and see if you can decide on one that has the "best" data on it. Ideally it would come up clean via both DU and DW (after any repairs, if necessary).
It would be wise to check that it's a known good drive as far as booting, has the current data you need, etc. Don't be afraid to open some files to check they are working, that sort of thing. Once your are satisfied all is well, designate that drive as the master for backup purposes. You could then, if necessary, copy any recent files you've been working on to that drive in an attempt to make it the most up-to-date drive you have to work with.
Assuming you can designate one such drive as the "master", then I would suggest you reformat one of the remaining two, intended as a backup, after first zeroing data to map out potential bad sectors. If it were me, I'd use an external for the first clone if I had a choice.
Again, run your usual repair routines on that to make sure it's a good, working clone.
That should still leave you with one drive that may have problems. If you are satisfied the master and the clone are known good, you could then do the zero/reformat/file check on the third.
Again, were it me, I'd leave the internal for this last exercise, but which drive this may be could be limited by what you discover when you look for a "best" drive to work from.
After all that, you should have one "master" and two good, known working clones. If that's the case, you could then (and only then) go about eliminating the possibility of bad sectors in the "master" drive with a zero, reformat, etc, taking the data back from one of the known good clones you made.
At that point, all three drives should be in top-notch condition with good data and no bad sectors. If problems develop later on one, that points to a declining disk that should be replaced soon, as it is likely to become increasingly unreliable.
The internal will be able to benefit from SMART reporting, so by all accounts it should be the one in best shape as far as low-level issues go, since any problems should have been flagged if you use a SMART reporting utility.
Disk Utility in any case should give you a SMART status on it, if you don't have a 3rd party monitoring utility installed.
Remember that when formatting drives, you must be clear in your head what is going on and insure you always have a drive with known good data on it. If there's any doubt, stop and think it through. You don't want to end up with three nice, formatted, empty drives and no data.
The only other thing I can think of is if you can remove the externals from the enclosure and install them internally on a Mac (without too much trouble) you could get a SMART status report on them, which might be helpful.
Last edited by gordguide; May 7th, 2010 at 10:58 PM.
Disk Utility and Disk Warrior perform different functions; one is not a replacement for the other, nor would I expect them to find the same issues.
I thought disk utility would check the whole disk in general and all areas of the data structure and repair pretty basic problems to the degree it could whereas DW was specifically designed to rebuild the directory (which I assume is where a lot of problems reside if one has problems.
I just ran the "Repair Permissions and File and Folder Check" on DW to see if anything interesting comes up.
On permissions there were two that were corrected with a final note that all is OK
With the file and folder check,
The property list, resourcedata, folder depth and system symboliv link files were checked with no problems found with any of them.
Then detected that the resource header of one file was damaged and could not be repaired - this was in the library folder of a printer which I no longer use - it has died, so I could delete that file
DW also detected property list damaged and could not be repaired in library/preferences.
That was all.
Then ran DW again rebuilding the directory with the same results as the first time around.
Quote:
If DW cannot replace the directory, that does suggest some low-level issue. Assuming you don't need the backup for immediate recovery, I would do a reformat and clone a second time with CCC.
If I launch the problem hard drive, the one that won't boot, it looks as if all the data is actually there so I'm going to leave that alone for now since I don't have a second up-to-date back up of the external I'm running with.
But I have another internal drive with a 200 Gig partition that I can erase and clone the external to and that is what I will do.
But I'll do a complete clone, not incremental, just need to decide if I use CCC or Super Duper. I'll probably use SD since I'm a little bit leery of CCC - it gave me the external that doesn't boot every time.
The problem drive btw is an internal SATA drive and SMART comes up clean.
I just see that you have added to your earlier post
Quote:
Originally Posted by gordguide
It might be that in cloning from/to the three drives you have inadvertently copied the problem to the others ... i"m not exactly clear on what you have done so far. But, a bit-for-bit copy, which a true clone should be, could certainly do that.
With CCC I always end up with a file level clone automatically for some reason.
This time, there were only two drives involved.
Drive "A" was the original internal 1.5 TB drive I was using two weeks ago.
Cloned that to a 2.5-inch FW external (drive "B") that I took with me on a trip.
User drive "B" on another Mac for the two weeks, when I came back I booted up on drive "b" since it had all the latest changes on it.
The drive was getting pretty full, about 150 GB of the 200 GB partition on it, so I decided to move about 60 GB of data to a different internal, drive "C". That was data that wasn't going to be updated or changed so I saw no point cloning it back and forth. I just make one back up of that data and leave it at that.
After getting the data on external drive "B" down to 90 GB I did the incremental clone to the original drive "A".
There would have been a fair amount of data on drive "A" at that time that no longer existed on drive "B" I was cloning from, but I thought the incremental clone would take care of that per the CCC documentation.
Maybe that's where things went wrong.
So right now I have one external that seems to be fine and one internal that won't boot, where I can't get DW to rebuild the directory but which seems to have all the data intact as far as I can tell.
Let me run disk utiliy and DW on the external before I do any cloning.
Oh - and that's why I even came back to ehMac right now and saw your additional posting - if I zero data to map out bad sectors, will disk utility tell me if it found any and how many?
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Instead of a CCC incremental from your external to your main drive I'd suggest doing whatever CCC calls a Total clone back to the main drive.
It's no good now the way it stands, so this total cloning cannot hurt anything.
Better still, download and run the free version of SuperDuper (external ->main) just for the hell of it, and report back the results.
" ... Oh - and that's why I even came back to ehMac right now and saw your additional posting - if I zero data to map out bad sectors, will disk utility tell me if it found any and how many? ..."
No, it will just do the job quietly.
As I said earlier, drives often have bad sectors right from manufacturing. There will be "hidden" areas of the drive that are reserved for use as a replacement sector for bad sectors. So, the total size of the drive (in bits) won't change as long as there are sufficient spare sectors available to replace the bad sectors in the area normally formatted.
What could happen is the total size as reported by a disk utility could change (downward). That would happen if all the reserved sectors are used up, and the additional bad sectors are simply marked "dead" and not available for data. Since these will be in the useable area of the disk, there are no "spare" sectors available to take their place, so the net available size must therefore fall below what the normal formatted size was previously.
That would be a solid indicator of a disk that should not be relied upon any longer, broadly speaking it suggests the disk is failing and is likely to continue to have more and more unreliable sectors show up over time. Since a write may be allowed (the sector is marked "available") but the data written there is probably corrupt, the drive is beyond usefulness at that point. Corrupt data generally is lost forever.
It's very difficult to say what, exactly, would be copied by a bit-for-bit clone by a utility such as CCC. The safest approach would be to copy the data only, and leave areas reserved for the OS (like the directory) to be managed by the OS.
A true bit-for-bit clone will copy everything ... even the formatting ... to the new disk, but I would be very surprised to learn CCC does that. Certainly older versions did not, which is why if you replaced a drive in an iPod, you had to resort to the Terminal to recreate the special iPod partitions.
Law Enforcement use special forensic disk clone hardware to make bit-for-bit copies of every area of a disk. Obviously if a utility or OSX itself could do so, these tools would be unnecessary.
Last edited by gordguide; May 8th, 2010 at 01:53 PM.
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