I was starting a backup of Acer's factory restore partition located inside of an extended partition to determine whether or not it still worked. I clicked "take no action" once I saw that it had, in fact, successfully started up. However, when I rebooted, I got an "error: no such partition" and was dropped to a GRUB recovery prompt.
Upon further investigation, I discovered that all partitions inside the extended partition were gone except for the recovery partition!
What happened? How can I fix this?
testdisk doesn't find the deleted partitions!