Disk utility invalid free block found

I ran Disk Utility because my computer seemed slow. DU said that I needed to restart and repair, but when I did that, DU said that the disc was fine. After re-starting, DU again said that it needed repair. The exact message was: "Invalid free block found (it should be 48071714 instead of 47831211) File system check exit code is 8"
Still running pretty slow. Don't know what the deal is.
Thanks!

A disk that has been "repaired" by Disk Utility has already failed and will fail again, probably in a very short period of time.
Back up your Mac if you have not done so already. To learn how to use Time Machine read Mac Basics: Time Machine backs up your Mac - Apple Support.
Replace the hard disk drive, or take this as an opportunity to upgrade to a SSD.

Similar Messages

Invalid free block count

Hi,
Earlier today I wanted to use the boot camp utility to install WinXP on my MBP. I decided to set the partition to about 60 Gb of space for Windows, but the utility crashed from some reason. (The screen went slightly dim grey and the message "please restart your computer now" appeared).
So I restarted the computer, but now, the 60 Gb I allocated for the new partition has been interpreted by the OS as used space on the Mac HD. I tried running Disk Utility to verify what was going on, and I get the message "Disk repair failed, invalid free block count".
How can I get my free space back? Do I really need to use the Leopard dvd to run disk utility again? I hope not, because I left the dvd at my other house, that's pretty far away from where I am right now. Any help would be appreciated! Thanks.

I don't know that Disk Utility can help since it will not repair the corrupted Boot Camp partition. You can run Boot Camp Assistant and see if it will remove the partition. If it cannot, then the next steps can be a gamble so you should backup your OS X partition in case you may need to repartition the drive.
If you cannot remove the partition with Boot Camp, then you can try this:
Open Disk Utility, select the drive entry (mfgr.'s ID and drive size) from the left side bar, then click on the Partition tab in the DU main window. You should now see the partition sizing graphic. Hopefully you should see two partitions. The top partition will be your OS X system volume. The bottom partition should be the one Boot Camp tried to create. Click in the bottom partition to select it (you will see it will be outlined in blue) and click on the "-" button in the lower left corner. The partition should then be removed. Click on the Apply button and wait for the process to complete. If the process fails then you will have to start from scratch and repartition the entire drive. Your OS X installation will be lost. This is why you need to make the backup in advance. If it does work then select the sizing gadget in the lower right corner of the remaining partition and drag it down to the bottom of the sizing window, then click on the Apply button again. Wait for the repartitioning to complete.
Just to be on the safe side I would repair the drive:
Extended Hard Drive Preparation
1. Open Disk Utility in your Utilities folder. If you need to reformat your startup volume, then you must boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger or Leopard.)
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Click on the Options button, set the partition scheme to GUID (only required for Intel Macs) then click on the OK button. Set the number of partitions from the dropdown menu (use 1 partition unless you wish to make more.) Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the volume(s) mount on the Desktop.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
Steps 4-6 are optional but should be used on a drive that has never been formatted before, if the format type is not Mac OS Extended, if the partition scheme has been changed, or if a different operating system (not OS X) has been installed on the drive.

Disk Utility - Erase Free Space-what does it really do?

Hey Forum,
I am using mac os 10.6.4 on my macbook and i have a doubting question for quite sometimes, what does disk utility erase free space feature really do? Does it gives you more free space? or what? I know it prevents the recovery of deleted files but i want to know what more it does and do not do? Like, now my hdd free space kept increasing and decreasing, by a few 100 mbs or 50mbs etc, so do i erase free space so to solve this problem? Ok, i do not only want to know does it solve the previous problem, but also the questions stated in the whole long paragraph i have wrote. If you know anything related to disk utility's erase free space, feel free to tell me!
Pls help me, I need you guys' help!
Thank you.
Regards
Ala.

Erase free space simply writes zeros over the space occupied by deleted files to prevent data recovery. That's all it does. It does not give you extra disk space.
Your disk space goes up and down a bit because the system creates temporary files and logs which take up space, such as the Safari cache. You can clear these file using a utility like Onyx (which is free)

Killed Disk Utility Erase Free Space. Now 0 available

(I erroneously posted this earlier to the Safari forum; posting here again)
I ran Disk Utility "Erase free space" on my iMac G5 250GB boot drive (I had about 130GB free). It ran for about 50 minutes, and got to "creating temp file" and then seemed to hang (thermometer didn't move for 20 minutes). So I force killed it. It seems to have left that "temp file" that takes up all available space since Disk Utility now reports 0 bytes available (and MS Entourage says insufficient free space and exits). I ran Finder "Secure empty trash" to delete 57 files with no error. But Disk Utility still says 0 bytes available.
First Aid "Verify Disk" reports no problems. "Verify Permissions" reports no problems.
Is there a way to regain my available space?
Thanks,
Ken

Restart did it. Thanks very much.
Ken

Tip on How to Monitor Disk Utility Erase Free Space

When you use the Disk Utility Erase Free Space option, it can sometimes appear to hang and the progress bar isn't always a help.
By accident, I discovered that if you run the Activity Monitor and select Disk Usage, you can in fact monitor progress. The Space Free will gradually tick down, sometimes as slowly as 100K/sec, then when it hits zero, it will quicklt tick back up. If you observe this, just let Disk Utility complete to avoid any issues; Activity Monitor makes it easier to be patiet about this.
Hope this helps.

Great tip, thanks for the post!

SSD - Disk Utility - Erase Free Space

Hi Community,
does the function in disk utility, which erases the free space by writing zeros into it, in context to a SSD drive the same like a block refresh which some drive vendor utilities does to increase the write performance? Or is a block which contains only zeros not really empty for the SSD controller?
Thx & Bye Tom

I am guessing a little here, but I suspect that "Trim" support ensures that data in free space can't be reaccessed once the files are deleted.
Another guess is that erasing the SSD free space may not be a great idea from the point of view of unnecessary writes and also filling the entire usable space up with what may appear to be data.
We are also discussing this subject in a German newsgroup and there we came to the result that the only way to inform the SSD-controller that the content of a specific block is invalid, is either to overwrite a specific logical address, so than the controller knows which physical blocks are invalid or to send the TRIM command.
To write zeros into the empty space is from the controllers point of view only content and will result in a full SSD drive afterwards. As longer I think about this as more I belief that this is correct and the use of the disk utility to refresh a SSD drive isn't the best idea... ;-)
Bye Tom

Disk Utility: for bad blocks on hard disks, are seven overwrites any more effective than a single pass of zeros?

In this topic I'm not interested in security or data remanence (for such things we can turn to e.g. Wilders Security Forums).
I'm interested solely in best practice approaches to dealing with bad blocks on hard disks.
I read potentially conflicting information. Examples:
… 7-way write (not just zero all, it does NOT do a reliable safe job mapping out bad blocks) …
— https://discussions.apple.com/message/8191915#8191915 (2008-09-29)
… In theory zero all might find weak or bad blocks but there are better tools …
— https://discussions.apple.com/message/11199777#11199777 (2010-03-09)
… substitution will happen on the first re-write with Zeroes. More passes just takes longer.
— https://discussions.apple.com/message/12414270#12414270 (2010-10-12)
For bad block purposes alone I can't imagine seven overwrites being any more effective than a single pass of zeros.
Please, can anyone elaborate?
Anecdotally, I did find that a Disk Utility single pass of zeros seemed to make good (good enough for a particular purpose) a disk that was previously unreliable (a disk drive that had been dropped).

@MrHoffman
As well pointed your answers are, you are not answering the original question, and regarding consumer device hard drives your answers are missleading.
Consumer device hard drives ONLY remap a bad sector on write. That means regardless how many spare capacity the drive has, it will NEVER remap the sector. That means you ALWAYS have a bad file containing a bad sector.
In other words YOU would throw away an otherwise fully functional drive. That might be reasonable in a big enterprise where it is cheaper to replace the drive and let the RAID system take care of it.
However on an iMac or MacBook (Pro) an ordinary user can not replace the drive himself, so on top of the drive costs he has to pay the repair bill (for a drive that likely STILL is in perfect shape, except for the one 'not yet' remaped bad block)
You simply miss the point that the drive can have still one million good reserve blocks, but will never remap the affected block in a particular email or particular song or particular calendar. So as soon as the file affected is READ the machine hangs, all other processes more or less hang at the same moment they try to perform I/O because the process trying to read the bad block is blocking in the kernal. This happens regardless how many free reserve blocks you have, as the bad block never gets reallocated, unless it is written to it. And your email program wont rewrite an email that is 4 years old for you ... because it is not programmed to realize a certain file needs to be rewritten to get rid of a bad block.
@Graham Perrin
You are similar stubborn in not realizing that your original question is awnsered.
A bad block gets remapped on write.
So obviously it happens at the first write.
How do you come to the strange idea that writing several times makes a difference? How do you come to the strange idea that the bytes you write make a difference? Suppose block 1234 is bad. And the blocks 100,000,000 to 100,000,999 are reserve blocks. When you write '********' to block 1234 the hard drive (firmware) will remap it to e.g. 100,000,101. All subsequent writes will go to the same NEW block. So why do you ask if doing it several times will 'improve' this? After all the awnsers here you should have realized: your question makes no sense as soon as you have understood how remapping works (is supposed to work). And no: it does not matter if you write a sequence od zeros, of '0's or of '1's or of 1s or of your social security number or just 'help me I'm hold prisoner in a software forum'.
I would try to find a software that finds which file is affected, then try to read the bad block until you in fact have read it (that works surprisngly often but may take any time from a few mins to hours) ... in other words you need a software that tries to read the file and copies it completely, so even the bad block is read (hopefully) successful. Then write the whole data to a new file and delete the old one (deleting will free the bad block and ar some later time something will be written there and cause a remap).
Writing zeros into the bad block basically only helps if you don't care that the affected file is corrupted afterwards. E.g. in case of a movie the player might crash after trying to display the affected area. E.g. if you know the affected file is a text file, it would make more sense to write a bunch of '-' signs, as they are readable while zero bytes are not (a text file is not supposed to contain zero bytes)
Hope that helped ;)

Disk Utility- Invalid Sibling Link

Can anyone tell me what this is about
Verifying volume “G5 HD”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid sibling link
The volume G5 HD needs to be repaired.
Error: The underlying task reported failure on exit
1 HFS volume checked
Volume needs repair
I had a similiar problem and posted this
http://discussions.apple.com/message.jspa?messageID=3486224#3486224
I have erased and installed the complete system (10.4) again and only been using Safari and ichat for a few days. I have updated all software etc.
I was about to migrate all my files back from an External HD FW and decided to Verify the disk quickly and this message came up.
Do i have to buy another hard drive?
If so what do you recommend? (about 250gb)
G5 2.3DP Mac OS X (10.4) G3 Pisimo 400, Maxtor 250gb External FW HD, ipod etc

If you have erased (but not zero'd the drive) and re-installed 10.4 after the first problem, and then it has happened again, you could try an erase with zeros (select 'Security Options' in Erase) and a complete new install of 10.4 and combo update to 10.4.8
http://www.apple.com/support/downloads/macosx1048comboupdateppc.html
'Zeroing' is supposed to map out the bad blocks on the drive so that they are not used.
When you have re-installed, you could run Disk Utility(the one on the 10.4.8 drive) and Verify Disk on the boot drive a couple of times. If there is any sniff of an error, see below.
But you may feel happier to replace the drive, as they are not that expensive. I have a Seagate 300GB as the second, 'data' drive, which was a good size/price combination at the time of purchase, but you may want a smaller, faster one as your boot drive. You will find many recommendations if you browse/search the forum.
Note that it is not impossible that other problems are causing the directory corruption - but getting the drive running right would be my priority. Good Luck.

Disk Utility: Invalid Directory Item Count

I have noticed a minor problem with my Mac Pro when restarting. Sometimes it will fail to restart correctly and simply displays the grey screen (but not the apple icon). Usually powering down the Mac Pro will get it to start up correctly. Not ideal, but manageable.
I ran Disk Utility earlier to check what may be causing this issue and was given the following after Verifying Disk:
Verifying volume “Macintosh HD”
Checking file systemPerforming live verification.
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Invalid directory item count
(It should be 33 instead of 32)
Checking extended attributes file.
Checking volume bitmap.
Checking volume information.
The volume Macintosh HD was found corrupt and needs to be repaired.
Error: This disk needs to be repaired using the Recovery HD. Restart your computer, holding down the Command key and the R key until you see the Apple logo. When the Mac OS X Utilities window appears, choose Disk Utility.
If I restart and launch Recovery HD will I lose any data or mess things up? The machine works perfectly fine once booted and I was none the wiser to this error until I ran disk utility. The timing is unfortunate as I have just ordered a replacement drive for Time Machine due to an unrelated external hard drive error, so I don't have a recent backup which is a bit unnerving.
I want to run Recovery HD but I'm worried its going to cause a problem on an otherwise fully operational machine. I don't want to create an issue unless there is one (especially when I dont have a secure backup for a few more days). I also have Disk Warrior which has been fantastic in the past, but I cannot use it on the Mackintosh HD as it wont allow rebuilding of the startup disc.
So my question is: Should I run recovery HD now or just wait until I have a secure backup just in case it screws up? Is it possible Recovery HD may "create" a problem for me on my machine which runs and operates perfectly (minus the restart problem).

I went into Recovery HD and ran Disk Utility. It verified and repaired the permissions without any data loss or problems. As a bonus the boot problem seems to have been recitifed.

Disk Utility reports a block count error for a deleted file?

I carry out a regular scan of the hard drive and on occasions disk utility reports that a file has a bad block count. It is usually a large file like a CR2 or TIFF and is also one which has been deleted? Not only put in the trash but emptied the trash as well.
The only other thing of note, which I havn't checked if it is relevent to my problem, is on occasion when I go to empty the trash it reports it can't be fully emptied as one of the files is still in use, even though it isn't? If I use secure empty trash it dletes the file.
In case its relevent:
I use Canon's DPP & ACR for CR2 files and PS CS6/CC for TIFF's. I also delete TIFFS from within Bridge CS6/CC.
Both Disk Utility and Drive Genius report the SMART status as being OK.

Hi Hollie, and welcome to the forums!
Have you created images before successfully?
Is this to/on your boot drive, or an external drive?
Have you done any Disk/OS maintenance lately?
We might see if there are some big temp files left or such...
How much free space is on the HD, where has all the space gone?
OmniDiskSweeper is now free, and likely the best/easiest...
http://www.omnigroup.com/applications/omnidisksweeper/
WhatSize...
http://www.macupdate.com/info.php/id/13006/
Disk Inventory X...
http://www.derlien.com/
GrandPerspective...
http://grandperspectiv.sourceforge.net/

Disk Utility - Erase Free Space

Hey Forum,
I am using mac snow leopard on my macbook and I wanted to erase the free space on my hard drive, so is the zero-out free space enough, or do I need the 7-pass erase free space. I just wanted more disk space, thats it. So can anyone tell me what are each options for? And do i need to 7-pass erase if i just wanted more disk space?
I await your favorable replies.
Thank you.
Regards.
Ala.

As The hatter says, the erase free space option has nothing to do with creating more free disk space -- the space is already free.
If you are confused about this, just open Disk Utility to the "Erase" tab & click the purple question mark at the bottom of the window. This will open Disk Utility Help to the topic *Erasing disks*. Refer to the last subject, *Securely erasing empty space* & if necessary click the link below it to go to the help topic *Erasing free disk space*, which explains this function in more detail.
FWIW, should you ever need to use this security function, a one pass secure erase is probably adequate to make the data unrecoverable.

7-pass, or zero out-Disk Utility Erase Free Space

Hey Forum,
I want to clear my erase free space on disk utility. And I am confused, whether to use 7-pass or zero-out? Any suggestions which one to use. Is zero out enough, or is 7-pass too much, any suggestions of whether to use either of them is appreciated, thank you.
Ala.
P.S. What are zero-out, 7-pass, and the 35 thing for and their differences?

There is no need to post the same question twice, especially in the same forum.
Regarding what you can find with Google, an overly simplified or out of date treatment of the topic may lead you to the wrong conclusions. For example, the DoD 5220-22M standard is obsolete (& never recommended a 7 pass erase to begin with) & the 35 pass erase was intended for old, pre-2001 drives.
For modern ATA drives like you will find in any Mac capable of running Snow Leopard, one or at most a few zero data passes will do all any software-based secure erase method can do.
If you need verification of that, refer to the Epilogue section of Secure Deletion of Data from Magnetic and Solid-State Memory, the seminal paper on the subject by the author of the 35 pass method.

Disk Utility Erase Free Space Option Nonexistant

Have an iMAC 1 GHZ PowerPC G4 256 MB DDR SDRAM OS 10.3.9. According to various google results I should be able to call up Disk Utilities>Partition>Erase>Erase Free Space. Its not there. (Its exactly where it should be on a nearby G5 running 10.5.8.).
It will allow me to erase the entire disk or either of two partitions but the Erase Free Space isn't just grayed out, it is completely missing.
1) The hard drive was partitioned at some point in the past I think to get around some admin thing. One partition has 51 out of 60 GB filled, the other has 12.4 of 16.3 GB filled.
2) Don't ask about the admins, my Entourage has been broken for 9 months - I am not joking.
3) My computer knowledge is spotty - you've been warned.
Help!

Try starting the iMac in Target Disk Mode while attached to one of your newer computers with a firewire cable. This basically makes the iMac an external hard drive. I've not tried this but you should then be able to use a newer version of Disk Utility on that drive.
[How to use FireWire target disk mode|http://support.apple.com/kb/HT1661] includes description of hardware and software requirements.
[What to do if your Mac doesn't enter FireWire Target Disk Mode|http://docs.info.apple.com/article.html?artnum=75414], also read about [Open Firmware Password Protection|http://www.apple.com/support/downloads/openfirmwarepassword.html] which can disable Target Disk Mode.
I'm not a technician but I don't think it "misses" areas, it's just more a matter of covering up what was written there before. Think of it as you write something on a piece of paper, then erase it and write something down in the same space. If you look closely you can see what was written there before. Now erase that again and write something else. It'll be pretty difficult to make out what was written there the very first time. Do that 7 times and it will be very, very, very difficult. Do that 32 times and it will be impossible. However, all that erasing and writing will take its toll on the paper and take a long time. I'd say anything more than a erase once would really have to be justified by very sensitive data. Anybody wanting to recover the data would have to use pretty specialized equipment.

My HD in disk utility shows free space of 200GB and is greyed out. I am unable to do anything with this free space.

I dual booted my mac until recently with refind. It all worked fine until recently when i tried to remove the ubuntu partion as I did not need it any more.
Unfortunately, I am now not able to do anything to the 200GB of free space that shows in disk utility. Please help.
I use Yosemite now.

worked it out. thanks:)

Start-Up: Folder with gray question mark / Disk Utility: Invalid Sibling Link

Yesterday, I was working on my computer and it froze up. My only option was to reboot by holding down the power key. When the computer restarted, the screen was all grey with a folder in the middle of the screen with a question mark.
I tried the following:
1) Boot up computer while holding down the "Option" key. - Didn't work.
2) Boot up the computer while holding down the "Shift" key. - Didn't work.
Since the first two options didn't work I inserted the original system install disk and booted up while holding down the "C" key. I selected "English" as the language and then opened "Disk Utilities." I pressed "Repair disk" within First Aid. The message I am getting is as follows:
"First Aid failed. Disk Utility stopped repairing "Macintosh HD" because the following error was encountered: Filesystem verify or repair failed."
The details screen shows the following:
"Verify and repair volume "Macintosh HD"
Checking Journaled HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid sibling link.
Rebuilding Catalog B-tree.
The volume could not be repaired.
Error: Filesystem verify or repair failed."
I ran the "Repair disk" function about 6 times but it was not successful.
I was then going to try to do an "Archive and Install" from the original system disk but when I go to do that no destination options appear at the "Select Destination: Where do you want to install Mac OS X?"
I have not backed up my data very recently (and a lot of what I have stored on this computer is work - I am a freelance designer) so I would like to do something that at least allows me to transfer my data off of my hard drive before reformatting or anything like that. Of course, if there is a less intrusive fix that can leave my hard drive in tact, that would be ideal.
Any advice? Tips? Solutions? I have a MacBook Pro, 15" that I purchased 3 years ago (my 3 year Apple Care plan just expired about a month ago).

You are in a tough situation. The disk appears unusable according to Disk Utility. As was suggested you may (only may) be able to salvage it with Disk Warrior (not sure about Data Rescue). DW can sometimes recover a drive that DU can't. But nothing else can be suggested.
If you can get that disk recovered then back it up ASAP, wipe the disk, reinitialize it, and verify it. But I'm the paranoid type, and with the kind of errors you show for that disk, I am not sure I would ever trust it again. At most I would relegate it to a scratch disk.
Note, if it is a drive that you bought, most drives have a 3 to 5 year warrantee period, so you could get it replaced by the manufacturer if it is within that warrantee period.

Disk utility invalid free block found

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