I don't know enough about the nature ext2/ext3 to know the answer to this for myself:

I know I can use the "dd" command to create/restore an image of a USB flash drive. But can I safely write the image out to a USB flash drive that's larger than the original? Or is there something in the ext metadata which would then be incorrect and either result in only the original capacity to be accessible, or cause some other form of corruption?

If you have the USB image saved, there's nothing to stop you from just trying

But to answer your question: it depends on what your image is. Did you image the entire USB drive or did you image a partition?

For instance (full USB drive):
or (for a partition):
If your image is of the full USB drive, you should be able to write the image file to the bigger USB drive and then run gparted. gparted will allow you to resize a partition--letting you use the full space available on the larger USB drive. gparted will also run the necessary commands to update the ext filesystem (like adding more superblocks) to make the extra space usable.

If you have a partition image, it should be similar. But you will need to restore the image to an existing partition. That partition should be the same size as your original. Once restored, then you can use gparted to adjust the size of the partition like above.

I should point out that gparted is just a frontend for various tools. You could perform all the tasks gparted does by hand. But I don't remember the name of the ext program that grows/shrinks a filesystem off-hand.

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Heh, yea. I guess I was afraid of possibly ending up with it appearing to work but having subtle problems.

Thanks!

Could be a problem if you were using GPT partitions as they have a backup header at the last sector of the drive.

Most usb drives are "floppy formated" though and this is only really a concern for real drives.

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