Mac HD displays as "media" in disk utility, Other problems.

Hey all,
I've got a couple problems here.
First being my hard drive is failing, I am aware of that. Not much I expect from you guys for that.
Second, my backup files have been corrupted and unusable.
Third, I can not get to single user mode.
Fourth, permissions on startup disk are most likely corrupt, stalling the system.
Fifth, Disk Utility identifies the startup disk as "media" using install CD.
So here's the deal. It started as: I suspect I had corrupted files in a folder that I can neither find nor rectify.
Upon doing backups with time machine, The program & computer would freeze for hours on end (most likely hung up on this/these corrupted files), no new backups resulted, and for some reason the original backup from a year ago disappeared. This could have been a problem from a failing harddrive, I'm not sure.
Which leaves me with no backup to start over from. (And a total loss of years of photos and documents) :-(
I can not load osx from the hard drive, it just gives me the hopeless folder with a question mark. I have tried Cmd-S, to no avail. No safe mode and holding Cmd on startup gives me nothing.
I have done the Cmd-Option-P-R with success but no helpful fixes.
So, I can sometimes, with luck, restart the computer (no buttons pressed) and I will get to the blue screen before the log in window (computer set up for multiple users, but only because of migration's automatic setup on a new computer)
But I get the spinny gear and then a sort of reset back to the blue screens (light blue, darker blue, spinny gear, reset, repeat).
I assume this has to do with a screw up in permissions or privileges amongst users and is confusing itself.
I suspect that there was an issue with backing up files in relation to this.
What if anything, can I do to reset the permissions/privileges without being able to get past the log in screen?
I can get to the Disk Utility on the Mac OS install disk but it only identifies the startup disk as "media." I understand that it's most likely because of a failing hard drive.... But is there any way to access the hard drive before the CD install disk kicks in, or regular booting starts, in the off chance the hard drive is functioning?
Also, is the terminal on the install disk software able to run fsck?
Would it be possible to clone the hard drive info (if the hard drive still works) and pop it in the machine without recourse?
Any help is appreciated
Thanks

I have exactly the same problem.
Tried all the usual things, like safe boot, and PRAM resets.
Because the drive shows as a zero byte device you can't repair or reformat it.
I did managed to get it to correctly appear and run following a very cold reboot, but it soon vanished when running disk repair.
I fear that either my HDD or the controller is kaput? Any thoughts?

Similar Messages

I just restarted my mac then suddenly when it boots,disk utility came and says different option like repair disk, get help, reinstall OSX and I tried to click disk repair but it says that I am um able to repair the disk

i just restarted my mac then suddenly when it boots,disk utility came and says different option like repair disk, get help, reinstall OSX and I tried to click disk repair but it says that I am um able to repair the disk

It sounds like your hard drive either has a software problem that Disk Utility cannot fix or that the HD has failed (mechanically).
Your Mac may have booted either to your recovery partition or to internet recovery in an attempt to repair the drive- I can't tell from your post.
I'll assume that it was the recovery partition.
Try to boot into internet recovery (hold down option command R at restart), and see if you can repair your HD with Disk Utility. You should also repair permissions while you're there.
If that doesn't work, try to boot into single user mode (restart, hold down ⌘S until you see a black screen with white text) and repair your hard drive. Here's a reference with directions: Repair Your Hard Disk in Single User Mode | Everything Macintosh
If that doesn't work you have a few options:
If your mac originally came with installation disks, you can try to boot from the installation disk and then see if you can repair the HD.
There is a small chance that Techtool Pro 7 will be able to repair your HD if Disk Utility can't.
If none of that works then your HD has probably failed and will need to be replaced, which is not too difficult to do yourself if you can use a screwdriver.

Have a mac book pro that crashed. ran disk utility to repair. comp booted and ran for short time. then crashed. ran repair again. disk utility said it could not repair files and i needed to format hard drive and start again. now nothing works

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comp said it could not unmount disk and now when comp trys to boot all i get is a question mark on the screen. help

Erase and Install
1. Boot from your Snow Leopard 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 Utilities menu.
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. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
4. Quit DU after formatting completes and return to the installer. Install Snow Leopard.
5. After restart into Snow Leopard download and install Mac OS X 10.6.8 Update Combo v1.1.

TS2570 Question re: "Start from your Mac OS X Install disc; use Disk Utility"

I've worked my way through the step-by-step trouble shooting in the TS2570 article up to "Start from your Mac OS X Install disc; use Disk Utility". So far, every step results in the same outcome - my formerly trusty 2007 Intel duo core iMac (24") will not start up, freezing on a grey screen with a blinking question mark on a folder. I don't completely understand this next step. I have both a Leopard and a Snow Leopard disc. I'm not positive whether these were for the iMac, or my old Macbook Pro. I assume this makes a difference.

Question (?) Mark, Blinking Folder, or Gray Screen at Startup
These are related but not identical issues. Their causes are outlined in Intel-based Mac- Startup sequence and error codes, symbols. Solutions may be found in:
A flashing question mark appears when you start your Mac
A flashing question mark or globe appears when you start your Mac
Mac OS X- Gray screen appears during startup
In most cases the problems may be caused by one or more of these:
a. Problem with the computer's PRAM - See Resetting your Mac's PRAM and NVRAM.
b. Boot drive's directory has been corrupted - Repair with Disk Utility.
c. Critical system files are damaged or deleted - Reinstall OS X.
d. The disk drive is physically non-functional - Replace the hard drive.
Note that the information I have provided is what Apple recommends, If other users suggest different solutions than found here, then be sure what they recommend does not impact on your warranty, if any, or ability to get continuing Apple service.
Please don't start removing drives or changing cables unless you know what you are doing and have exhausted other non-invasive alternatives outlined here. If you perform any work yourself that is unapproved by Apple, then you will void any warranty you may have and lose all further Apple Support.
Repair the Hard Drive and Permissions
Boot from your Snow Leopard 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 Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.
If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.
The main difference if you are using Lion or Mountain Lion is that you must first boot from the Recovery HD. Simply boot from the Recovery HD to perform the above.
Reinstall Snow Leopard Without Erasing The drive
1. Repair the Hard Drive and Permissions
Boot from your Snow Leopard 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 Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.
If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.
2. Reinstall Snow Leopard
If the drive is OK then quit DU and return to the installer. Proceed with reinstalling OS X. Note that the Snow Leopard installer will not erase your drive or disturb your files. After installing a fresh copy of OS X the installer will move your Home folder, third-party applications, support items, and network preferences into the newly installed system.
Download and install Mac OS X 10.6.8 Update Combo v1.1.
Reinstalling Lion/Mountain Lion Without Erasing The Drive
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.
Reinstall Lion/Mountain Lion: Select Reinstall Lion/Mountain Lion and click on the Continue button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

Brand new Mac, had to erase drive through disk utility as time machine back up failed. Now disk utility only has the option to install Mountain Lion which my Mac won't allow. Anyone any ideas as my Mac won't load anything up but disc utility!

Brand new Mac, had to erase drive through disk utility as time machine back up failed on initial setup, USB cable popped out Now can only access disk utility as won't load to log in screen. The only has the option in disc utility is to re-install Mountain Lion which my Mac won't allow or loading another time machine back up but after an hour of it processing, that didn't resolve the issue either! The time machine back up is the latest back up of my Mac Book Pro which was using OS X Maverix. I'm guessing I'm going to have to take my Mac to the store but that would be a hassle so does anyone have any ideas?

Follow this guide using another Mac.
Insert your newly created Mavericks USB into you Mac, press the power button and then hold down 'option,' until it gives you an option to boot from the USB. You will then be able to erase the internal disk with Disk Utility and reinstall Mavericks straight after.
After that you should be able to use Migration Assistant to restore your applications and user data.

After Server Administration Software for 10.6.8 install on my mac- Now I can't use Disk Utility ?

I installed ServerAdministrationSoftware for 10.6.8 on my mac- NOW I can't use Disk Utility - get Dyld Error Message: Library not loaded: /System/Library/PrivateFrameworks/PlatformHardwareManagement.framework/Versions /A/PlatformHardwareManagement? Also, the only reason I installed this was for the Workgroup Monitor which kicks out the same error.
Any help would be appreciated!

FireFox can't open lots of files it isn't suposed to. DMG is opened by the Mac osx as a virtual volume file you just drag the FireFox icon to where you want it installed. Check your desktop for a FireFox volume... like a drive. Double click the DMG file if it is not there. This is how Mac works it has nothing to do with FireFox, many apps install this way!

Disk Utility sees problem invisible to Disk Warrior?

Hi all,
In brief: Disk Utility seems to think I've got a big problem, Disk Warrior seems to be unable to fix it.
More detail: I ran verify disk from Disk Utility and was told I needed to repair my startup volume. So I ran Disk Utility's repair disk function from the install CD and it was unable to repair the disk. It was also unable to repair permissions.
So I reached for trusty Disk Warrior and ran that. It rebuilt the directory, reporting various changes, eventually ending with zero errors. That should have fixed it, right?
But then I re-ran Disk Utilty and was told, again, that the disk needed to be repaired.
Here's what happened when I ran DU's repair function from the install CD:
- I selected only the volume containing Mac OS X for repair and Disk Utility reported there's an "invalid leaf record count (it should be 3 instead of 525) and also that '1 HFS volume repaired' but '1 HFS volume could not be repaired'. (I'd selected only my startup volume).
- The verify disk function reports the same
- The repair disk permissions function cannot complete its task. Its error message reads: "Disk Utility internal error: disk utility has lost its connection with the disk management tool and cannot continue. Please quit and relaunch disk utility."
So, I ran Disk Warrior AGAIN (2nd time) and sure enough, it reports that it successfully rebuilt the directory but that the rebuilt version has no changes from the original version (meaning it's ok, right?).
Needless to say, if my startup disk DOES need repair, I want to do something about it. But does it need repair? And if Disk Warrior can't fix it, what can? Could it be that Disk Utility is seeing a problem that's invisible to Disk Warrior?
By the way, I ran DW's manual diagnostic and it said the drive itself was operating normally.
Very grateful if any of you can give me some insight into this.
Jason
Dual G5 2.5Ghz 2GB RAM, Powerbook G4 1.33Ghz, iPod 60GB Mac OS X (10.4.8) 500GB internal HDD

Hi Allan,
Sure thing. Here's the business.
Disk Warrior (v3.0.3)
DW reports that it's successfully rebuilt a new directory each time I run it. I've run it three times now. The first time, there were differences between the original directory and the rebuilt version and it displayed a message coloured red describing this. On the subsequent two occasions, it has displayed a message coloured green and said there are "no changes to the number or contents of the files and folders" in the rebuilt directory.
DW's manual diagnostic reports that the drive itself is "operating normally."
DU
Running DU internally (from the volume that also contains 10.4.9), it can only 'verify', of course. The volume's name is 'G5 hard drive'. The full message is:
Verifying volume “G5 hard drive”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking multi-linked files.
Checking Catalog hierarchy.
Checking Extended Attributes file.
Incorrect number of Extended Attributes
Checking volume bitmap.
Checking volume information.
d.",1)
G5 hard drive
Error: The underlying task reported failure on exit
1 HFS volume checked
Volume needs repair
Running DU (repair disk) from the install CD (for Powermac G5, OS X 10.3.5) produces the following report:
Repairing disk for "G5 hard drive"
Checking HFS plus volume
Checking extents overflow file
Checking catalog file
Checking multi-linked files
Checking catalog hierachy
Checking extent attributes file
Invalid leaf record count
(It should be 3 instead of 422)
Repairing volume
The volume G5 hard drive was repaired successfully
Repair attempted on 2 volumes
1 HFS volume repaired
1 HFS volume could not be repaired
So let's say that DW is doing it all right, and the copy of DU on the install CD (10.3.5) is producing an inaccurate result because it doesn't match up with Tiger, I can understand that. But why would the same problem come up with DU run internally from (in the course of the last 24 hours) both 10.4.8 and 10.4.9 (because the problem survived my upgrade)?
On the other hand, Allan, possibly DW isn't the right tool for the job. In that case, do you know what is?
Thanks,
Jason
Dual G5 2.5Ghz 2GB RAM, Powerbook G4 1.33Ghz, iPod 60GB Mac OS X (10.4.9) 500GB internal HDD

My external HD won't mount anymore on Mac OS, Disk Warrior or TechTool Pro, but appears as "media" on Disk Utility. What do I do?

I have this 1 TB Caviar Black drive from WD, I've installed it on an external HD case and have been using to store large files like HD movies and old archive things. Its file system is Mac OS Journaled.
Last year, all of a sudden, it gave me the following error while trying to plug it in: "The disk you inserted was not readable by this computer"
I was mad and left it for dead while looking for a way to fix it.
Then, again all of a sudden, it started working again, flawlessly and without any problems.
It worked well for at least 5 more months and then BAM... same error again!
I've tried DiskWarrior, TechTool Pro, Disk Utility and nothing... The disk won't show up on any of these apps, except on Disk Utility as a "Media" drive with 0 bytes used and unformatted partition.
What do I do?
Could it be the external HD case?

It could be a problem with enclosure, but it also could be a problem with the drive itself or the drive is possibly corrupted. I would start by contacting WD tech support.
It may be possible to recover files from the drive using file recovery software:
General File Recovery
If you stop using the drive it's possible to recover deleted files that have not been overwritten by using recovery software such as MAC Data Recovery, Data Rescue II, File Salvage or TechTool Pro. Each of the preceding come on bootable CDs to enable usage without risk of writing more data to the hard drive. Two free alternatives are Disk Drill and TestDisk. Look for them and demos at MacUpdate or CNET Downloads. Recovery software usually provide trial versions that enable you to determine if the software would help before actually paying for it. Beyond this or if the drive has completely failed, then you would need to send the drive to a recovery service which is very expensive.
The longer the hard drive remains in use and data are written to it, the greater the risk your deleted files will be overwritten.
Also visit The XLab FAQs and read the FAQ on Data Recovery.
Otherwise, unless the drive fixes itself like before you should try repartitioning and reformatting to determine if the drive has failed or is now working properly.

"media" in disk utility???

ive been having issues with internal SATA drives in all of my schools 15 macpro systems since running leopard through 10.6.7 for about a year. at least 1 out of each 3 internal SATA drives, excluding the system drive, will not mount and appear as, "media," in the disk utility. i have rearranged the slot order of the drives and that is a temporary fix with the drive not mounting again within a few days. however, i can pull that drive out and put it in one of our lacie 4tb external bays and they work like a charm, 6 months and still going. why would a drive fail in the macpro but perform flawlessly in an external case? what does it mean when a drive appears as,"media," and verify or repair fails plus the size no longer is registeted by disk utility?

the size no longer is registered by disk utility?
That is a very strong indicator of a drive that has failed. If the drive controller cannot reliably report the drive size/capacity, the drive may have died. Without the drive size/capacity, the drive cannot be repaired.
But reporting the size/capacity in an external enclose should be no different from the size/capacity reported in an internal drive bay. The only difference is the alignment of the connectors, which is strongly influenced by the sled.
Are you using the correct sleds? They changed with the 2009 model.
Are you meticulous about inserting them so that they are correctly captured in all the metal tangs inside the Mac? Being sloppy might **** the drive at an angle.
Are the kids pulling them out and playing catch with them? Stranger things have happened.

HD listed as "Media" in Disk Utility

After a power-shutdown, my computer would startup and get stuck on a white/gray screen with a blinking question mark.
I booted from the OS X Install Disk and opened Disk Utility.
The volumes shown on the left are:
1. 5.1 GB Optiarc DVD....basically the Mac OS X Install Disk DVD. And...
2. A drive simply labeled "Media"
The "Media" drive is Serial ATA 2, internal connection type. Total Capacity is 0 Bytes.
How bad is this?
Again, thanks.
G

I have exactly the same problem.
Tried all the usual things, like safe boot, and PRAM resets.
Because the drive shows as a zero byte device you can't repair or reformat it.
I did managed to get it to correctly appear and run following a very cold reboot, but it soon vanished when running disk repair.
I fear that either my HDD or the controller is kaput? Any thoughts?

Grey bar at startup - Mac HD is greyed out in Disk Utility - Can't be repaired? Need to salvage my data!

Mac Book Pro -
My MacBook Pro (2008 Model) has been unable to start up - upon the start up screen when the grey Apple logo appears, I get a loading bar below it.
After about 15-20 minutes when the bar is almost complete the machine shuts off. There seems to be no way around it.
So I booted up my laptop in recovery mode, and opened Disk Utility to check my if there was something wrong with my drives -
my Macintosh HD (under the TOSHIBA drive) is greyed out. When I hit verify/repair it returns error messages and it remains greyed out.
I tried multiple times and a few times it stopped being greyed out on the sidebar, but even then it wouldn't let me verify or repair.
Not backing up my data recently is my obvious fault here, but I just wanted to know if there is ANY way to salvage my data.
Things I've tried:
1) Recovery Mode
     -Veryify/Disk Repair doesn't work
     -Time Machine can't seem to access my HD either (greyed out)
2) TargetDisk mode
     -I connected my MacBook Pro via firewire to my Mac Pro in TargetDisk mode and no Hardrive shows up on my finder.
Any advice appreciated, going to try and take it to a tech shop on Monday.
Thank you!

I would take out the HDD and install it in an enclosure and then connect that to the Mac Pro and see if there is any success.
If not, then look for data recovery software on the Internet. Most will have a 'trial' version that will indicate if the software will be successful or not, so you do not have to commit funds without knowing if it will work or not.
The last option is a professional recovery service. There will be no guarantees of success and the costs will be very high.
Ciao.

Mac OS X 10.5 Leopard Disk Utility is not responding?

Hi
Just purchased a new Mac and used Migration to get some applications from my old Mac.
I was hoping I was able to chose what it copied but it just copied everything.
I trashed what will not use ( a load of old applications that I don't use)
Thought it was a good Idea to run Disk Utility to check I had not trashed anything I need
BUT IT IS NOT RESPONDING! after two tries and and hours of waiting it just says
"Gathering disk information"
What's going on? What Have I done? Do I need to panic? What should I do?
Thank you!

Try starting the machine from the install disks and trying disk utility from that.

Mac Keep Ejects Installation Media, Hard disk is empty, How to install OSX

I installed Ubuntu in my Mac Mini, Later my apple wireless keyboards pairing is not working and to pair i need to have OS X installed, since no osx installed, to boot i used to press the option key. So now I formated linux, now my hard disk is empty no partition or nothing. But the problem is my mac mini keeps ejecting OS X installation media (original dvd set came with mac mini) but I can boot from ubuntu live cd. How can I solve this problem. Some one told me to reset my pram, but I was unable to do it. Pressing Command Option P R does nothing. Please help me out. without my machine working I'm like a dead man.

Yeah I managed to get one, and tried c key to boot from the disk. It doesn't work. The current status of my machine is. My hard drive is clean (unpartitioned space, I formated it). Still Mac Ejects OS X installation media which came with the mac mini, But I can boot using Ubuntu,Solaris,etc disks and I can install them. How can I install OS X in this situation. Since I'm doing my PG course in Computer Science, the system is an urgent stuff for me.. Please help me out.
And why mac is ejecting the actual original installation media even when it's taking all other disks ?? I tried two different disks to make sure if it's the trouble of the disk, but that's not the case. I only ejects OS X disks and ejects all OSX Disks (i tried tiger disk, and leopard disk)
Deepak

I formatted my mac and after installation went to disk utility to erase

hello
i wanted to get rid of everything so i backed up all the files i needed in an external hard drive
and then i shut down the mac and restarted inserting the 2 cd's after i was done i went to disk utility
and erased free space 35 times ,during this time i cannot update browsers, programs,and cannot download anything or create folders.
is that temporary and should i wait till it's done?
also what i read that it only erases items that were erased from the trash what about all the other files i had not put in the trash will that be somewhere in the system?
thanks
Message was edited by: cajred

If you use Disk Utility and choose the Erase Free Space option for any disk volume, it only overwrites the space Mac OS X lists as being unused. You choose this option to prevent someone from being able to recover a deleted file from your hard drive. When you empty the Trash normally, the actual data is not removed from the drive, only the pointer that tells the operating system where that data is located is removed, so it's possible to still access that data until the OS overwrites it. It's not just emptying the Trash, but unless something goes wrong, it should not erase the files on the drive you wish to keep.
And yes, it will indeed take a long time.
Message was edited by: Dave Sawyer

Disk Utility 13 problem with USB drives

There appears to be a problem with Disk Utility 13 (part of OS X 10.9). At least, so far as I can tell, everything traces back to this app, or possibly OS X 10.9 itself.
I recently upgraded my MacBook Air to OS X 10.9 (reformatted hard drive, installed system from scratch, updated with all the latest Apple updates). I pre-checked all my third party software to make sure it was 10.9 compatible before installing it after the system cleanup, so everything I’m running supposedly has been approved as safe for 10.9. But I’m seeing a problem formatting USB drives that I do not encounter when running under 10.8.
I have a Seagate STAA500101 (“FreeAgent GoFlex”) drive connected via Seagate’s USB3 adapter that I’ve used for some time as a Time Machine backup. Post-overhaul, I decided to erase the backup and start fresh. When I attempt to format it (single GUID partition) with Disk Utility, I see the following messages go by:
Formatting disk1s2 as Mac OS Extended (Journaled) with name Untitled 1
Could not mount disk1s2 with name (null) after erase
Then there’s a pause, and the format appears to conclude fine. But if I run a “Verify Disk” immediately, I get this:
Verifying partition map for “Seagate FreeAgent GoFlex Media”
Checking prerequisites
Checking the partition list
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking all HFS data partition loader spaces
Volume on disk1s2 has 0 bytes of trailing loader space and it needs 134217728 bytes
Problems were found with the partition map which might prevent booting
Error: Partition map needs repair because a data partition needs loader space.
As the drive has just been formatted, that seemed odd. I took it over to another Mac still running 10.8.5 and formatted it there — it worked just fine. Verified just fine. Took the drive back to my MacBook Air and tried to verify the disk — same failure.
I wanted to rule out bad media, so I took a Lexar 16GB USB flash drive and tried to format it with Disk Utility 13 — got the same problem.
The only success I’ve had formatting USB drives under 10.9 is to boot up into OS X Recovery. Disk Utility there formatted my Seagate drive without an error. But once I booted back into normal 10.9 operating mode, the drive once again fails to verify; it makes me leery about using it as a Time Machine backup.
I suppose it’s possible there could be some background component like Sophos causing problems when formatting drives, but if I format a drive via OS X Recovery or another Mac under 10.8, that wouldn’t explain why the drives fail to verify.
Anyone got any other observations on this issue?

Problem resolved. I'm posting this note for anyone else who might run into this situation and come across this discussion.
It actually did turn out to be Sophos -- Cloud, that is. I'd been using Sophos' free Mac antivirus software on a variety of systems but forgot that I was now testing out Sophos Cloud on my own MacBook, which is their new endpoint solution, and supposed to be compatible with OS X 10.9 (although the Mac version is listed as "beta") Sophos Cloud includes a new feature called Device Control which allows you to create a company-wide policy to control access to hardware such as USB drives, optical drives, etc. But apparently it's still pretty buggy. I had my Device Control configured with the default setting of "monitor but do not block" but it was most definitely gumming up the system. With Sophos Cloud installed, here's what happens if I try to run "Verify Disk" on any attached drive. Note on the left side how "disk2s2" shows as a sub-volume for each hard drive.
So if I uninstall Sophos Cloud, reboot and rescan, here's what I get:
Works fine. Note that the "disk2s2" subvolumes are also gone. This is the way Disk Utility also appears on a 10.8 or 10.9 system, even if you have the standard free Sophos for Mac software installed. It's only Sophos Cloud that's not playing nice. It also appears to have stopped me from being able to play DVDs from an attached Apple USB SuperDrive -- that problem was likewise solved by removing Sophos Cloud.

Mac HD displays as "media" in disk utility, Other problems.

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