Sparse bundle resources temporarily unavailable

Sparse bundle disk images may be created either for direct access or for applications such as Time Machine. As such, while some may be on local volumes, they are also commonly stored on network shares; however, regardless of their location, users may get errors upon accessing the files.

Apple Discussions poster Gordan Buchanan writes:

"I have a sparse bundle file on a network share that gives a 'resource temporarily unavailable' message when I try to mount it. Disk utility gives the same message when I try and do a repair."

This problem has occurred for users trying to manually mount Time Machine network backups as well as for images stored on local drives. In order to troubleshoot the problem, users have tried restarting computers to clear any background processes that might be interfering with the image mounting, but these attempts have been unsuccessful.

Some users have had this problem occur when they've tried accessing the Time Capsule sparsebundle disk images from another computer besides the one that was used to create the image, which indicates there may be a permissions issue of sorts, since the images continued to mount normally on the original computer.

In addition to permissions errors, one other possibility might be image resources still being assigned to a specific user or computer if the image was not fully unmounted. When users have attempted to access the images from different locations and then cancelled the mounting process, this has resulted in this 'resource temporarily unavailable' error for the images.

Sparsebundle images are multiple 8MB 'band' files that are represented to the file system as individual files. OS X stores these in a file/folder tree format, with the whole image "file" actually being theses 8MB files in a single folder along with some configuration files. As such, if any of the files are being accessed or are otherwise unavailable, users the system will pass this on as an error when users try to access the image.

The fixes for this problem involve freeing up any resources in the image that might be reserved by the system.

Fixes

Disconnect and shut down all computers that have accessed the image This problem may be a result of some connection to the image persisting even though users have unmounted the image. This is especially true if users have previously cancelled the mounting process, have been unable to unmount the image. As such, hopefully by restarting all computers that have accessed the images, the image's resources will be freed up for others to access.

Restart the network server Since the network server manages user access to files, if users have access to the server then restarting it might clear out any persistent connections or resource reservation that the server is imposing on the image. This may be more relevant for users who have had to force-restart the computer with the image mounted.

Mount image from a local volume and repair the volume Some users have these images on external NAS volumes, which also have USB or FireWire connections. As such, users can mount the external disks locally and then run repair processes on them and the disk image files using Disk Utility. Shutting down the NAS unit and restarting it may also help.

Open the image and view the band files Since sparsebundles are actually folders, users can right-click them and choose "Show Package Contents" to view the contents of the image file. Within the image folder there should be a few configuration files as well as a folder called "bands". Opening that folder and letting the system list the files (which might take some time as there can be thousands of them) seems to ensure the files get accessed, and has cleared the problem for some users. Users should be sure to scroll down to the end of the list to ensure all files have been loaded and accessed by the Finder. When this is done, close the bundle and try mounting it again.

Replace the image's configuration files Replacing the configuration files in the sparsebundle folder has helped for some users. Right-click the bundle and show contents, and back up the three files located within it called "token", "Info.bckup", and "Info.plist". Then use Disk Utility to create a new sparsebundle image, and be sure to give it the following properties.

• Volume name: "Same name as the old sparse bundle"
• Volume size: any size
• Volume Format: Mac OS Extended (Journaled)
• Encryption: none
• Partitions: Hard disk
• Image Format: sparse bundle disk image

(NOTE: Since sparsebundle image files dynamically resize, the "size" field can be any size, but smaller numbers might be preferable since this is only a temporary image.)

Save the image to some location and then right-click it and "Show Package Contents" for it. Copy the three configuration files from it to the open "Contents" folder of the previous image, replacing the previous image's files. Then close the image and try mounting it again.

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