How to repair a filevault sparsebundle with disk utility?

Question

I've been experiencing some oddness with my filevault home directory so I wanted to drop into disk utility and run a check/repair on it. The odd thing is, when I log out and into another account, the sparsebundle says 0k in the finder, and appears to be a directory. When I sudo to cd into the directory, it appears to work, but I remain in /Users/username. When I drag the sparsebundle into disk utility, it appears in the bar on the left side of the screen, but clicking repair or verify causes the progress bar to activate for a split second then stop with no error message. Trying to mount the sparsebundle yields a "No supported socket" message.
I am able to log into the account. When I do that, in /users/.username directory, I can see the sparsebundle with its true size, 35 gigabytes.
I used to repair sparseimages; is the described behavior "normal" for sparse bundles and if so, is there a way to get them repaired in disk utility? Or is this odd behavior on the part of this particular sparse bundle?

Answer 1

Well a bundle and a disk image are both, likewise, "very different things" than actual independent storage devices, but disk utility is able to reason out that it needs to ask for the password for the disk image and open it in order to repair it. There's no reason why it couldn't be as bright when it comes to handling a sparseimage.
You are correct that mounting it first with a terminal command (sudo hdiutil mount -nomount -readwrite /path/to/sparseimage) causes it to be repairable in disk utility. Disk utility can figure out by itself that it needs to open the disk image when you repair a disk image, but apparently not with a sparsebundle. I disagree with your tone above that implies that somehow one would not expect disk utility to function robustly and be actually capable of repairing Apple file system-based virtual disk images (whether a single file or in a directory format, doesnt matter), and that one should be expected to dig up a terminal command and mount it manually before being able to tinker with it. That's not reasonable to expect of the user for a routine task such as repairing a disk image.
However on doing so, disk utility can repair the disk.
See:
http://blog.hardmac.com/archives/how-i-saved-my-corrupted-time-machine-sparsebun dle-image