Interrupted trims

A trim that is stopped or fails cleans up after itself. This page is about the rare case in which the application could not do that, because the computer lost power or the program was ended by force.

What can be left behind

While an image is being replaced, the trimmed image is first written beside the original under the original’s name with .vdtrim-tmp added. Once it is verified, the original is moved aside as .vdtrim-old, the new image takes its name, and the old one is deleted. For a disk made of several files, such as a split VMware disk, the two names are folders that hold the files.

Whenever the interruption happened, one complete disk exists: the original until the last moment, the trimmed one after it.

Cleaning up

When such an image is added to the list, the application notices the leftover files and asks whether to clean up. Clean Up puts the disk back in order. If the original is still in place, the unfinished result is removed. If it had been moved aside, it is put back; only for a disk of several files that was already wholly aside is the verified trimmed disk put in place instead. An image with leftovers cannot be trimmed until they are cleared.

The same is done from the command line with vdtrim recover image, which needs no licence. It never overwrites a file and deletes nothing but the two leftovers.