Kyoto University in Japan lost 77 terabytes of research data due to a defective software update issued by Hewlett Packard Enterprise (HPE) that unintentionally deleted backups.

The mid-December 2021 incident resulted in the loss of around 34 million files from 14 research groups. And data from four of those groups cannot be restored by backup, according to the university.

HPE issued a statement in Japanese and “took 100% responsibility” for the file loss.

The script update for Kyoto University’s supercomputer system originally was designed to “improve visibility and readability,” including a find command to delete log files older than 10 days, according to HPE’s statement translated by DeepL.

However, a defect occurred in the program that backs up the storage of the supercomputer system manufactured by Japan Hewlett Packard, which caused the script to malfunction. In consequence, some data of the high-capacity backup disc storage was deleted unintentionally, HPE stated.

“There was a lack of consideration in the release procedure of this modified script. … We were not aware of the side effects of this behavior and released [the update] by overwriting the script while it was still running,” the company admitted.

“This resulted in the reloading of the modified shell script in the middle of the execution, resulting in undefined variables. As a result, the original log files in [the high-capacity backup disc storage] were deleted instead of the original process of deleting files saved in the log directory,” HPE added.

Kyoto University suspended the affected backup process but planned to resume it by the end of this month after fixing the problem in the program. And it advised users to back up important files to another system.

Both the school and HPE claimed they will take measures to prevent a recurrence.