Boot drive (SSD) going read-only randomly

crashdisk-volumepermissionssd

I've got a mid-2010 MBP running OS X 10.8.4. I've got a Sandisk SSD as my boot drive in my Super Bay and a 1.5TB hard disk in my HD bay. (I realize I could get better SSD performance if I swapped those, but the HD is too tall.)

When I boot my computer, everything seems fine. But after varying amounts of usage time, the SSD goes unwritable until I reboot. It's extremely weird. I can't touch to create new files anywhere (I get an error message like "touch: test.txt: Invalid argument"), I can't save anything, and applications like Mail, which depend on disk access start crashing without error messages. The Console and logs don't seem to be revealing anything unusual. Disk Utility doesn't start and diskutil hangs. If I manage to run out my main memory, I get the "Boot disk is full, kill an application" message. But even more weirdly, for apps that don't need to save anything, the computer seems to work fine. Rebooting restores everything to normal temporarily.

I'm not sure if it's related, but I also have these sporadic periods of 10-20 seconds of spinning rainbow ball, where kernel_task is my highest CPU user and seems to block ALL other activity. Disk transfers, network transfers, and all else seem to come to a temporary halt until whatever it is its doing finishes. I can usually still Cmd+Tab to Activity Monitor during these seizures.

I brought it to the Apple Store today, and their diagnostics couldn't find anything unsually. They successfully repaired permissions in Safe Mode, but the problem still exists. The tech there said that it seems as though the kernel can continue writing to disk in this state, but nothing in user mode.

Anybody have any idea whatsoever what might be causing this? My only other option will be to reinstall the OS, but I'm trying to make that my last resort.

Best Answer

It is possible that you are using a disk driver such as fuse. If so, uninstall it.

I also have a 2010 MacBookPro with an SSD in my optical bay and a 750 gig drive. I found myself in a similar situation; unable to boot because my data drive randomly became read only at reboot.

The culprit was fuse. It decided to remove my mount point, and create a symbolic link in its place.

Try booting into safe mode by holding down the shift key, and removing any fuse like programs.

Check /Volumes for any symbolic links (Except for the symbolic link to / )

If the issue persists, try creating a new user account.

Lastly, because both sata ports are sata 2, it is unlikely you would see any performance increase by swapping drive locations.

Related Solutions

System Extensions Cannot Be Used Error

It looks like whoever it was at Logitech that created the Harmony 1000 Installer package for OS X had absolutely no clue how to do it properly.

The file permissions of the files that the installer package installs are completely botched. Some are set to a User ID and Group ID of 509 and 509, which doesn't even exist on my machine. (The initial OS X user has a UID of 501, and each additional user has the next higher UID. For example, 502, 503, etc. So, unless you have 8 total users, 509 won't even be defined on your system).

The file permissions of the .kext files it installs have a UID and GID of 510 and 510, respectively. OS X will refuse to load kexts unless they have the proper permissions. That means a user of root (UID of 0), and group of wheel (GID of 0).

[EDIT] OK, it appears that Logitech is actually installing the files with botched permissions and then "repairing" the permissions (setting a user of root and group of wheel) in the package's postflight shell script. (Ugh, even their script is noobish: prefixing every command with sudo is unnecessary, since the scripts are run as root anyway). While I guess that may work, it's kind of a backwards way of going about it. (They should have just set the proper permissions on the files they included as the payload of the installer package). And, obviously in your case, the postflight script must have failed during the installation, and has left those kexts with botched permissions.

You should be able to fix the permissions on the kexts by running the following AppleScript:

http://www.markdouma.com/developer/RepairLogitechHarmonyKexts.zip

Just download it, and double-click on the AppleScript to open it in AppleScript Editor. Then click the green Run button, and enter your password when prompted.

For the record, the script just runs the following chmod command:

do shell script "/usr/sbin/chown -R 0:0 
   /System/Library/Extensions/Belcarra.USBLAN_netpart.kext 
   /System/Library/Extensions/Belcarra.USBLAN_usbpart.kext 
   /System/Library/Extensions/RemoteControl.USBLAN_usbpart.kext;
   /usr/bin/touch /System/Library/Extensions"
 with administrator privileges

You may need to restart before the kexts will be loaded properly.

Hope this helps…

SSD Boot drive and encrypted HD

If you have an external drive where everything is backed-up, the easiest thing would be to erase the HDD choosing Mac OS Extended (Journaled) then restore from the backup.

Best Answer

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System Extensions Cannot Be Used Error

SSD Boot drive and encrypted HD

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