My operating system is installed on drive A, while a folder containing data is stored on drive B. Drive A has a bind mount that makes the folder on drive B accessible through a directory on the OS drive. If I boot from a USB installer and install a new distribution over drive A, will the contents of the folder on drive B remain safe?
3 Answers
The main risk is different from formatting a partition: a recursive file deletion such as deleting everything under a mounted directory can remove files inside the mounted filesystem. However, an installer formatting only the OS partition does not normally recurse through bind mounts onto another drive. If you want extra protection, disconnect or temporarily disable drive B during the installation, then reconnect it afterward.
If you’re reinstalling from a USB and only formatting or repartitioning drive A, the data on drive B should not be affected. A bind mount is just a kernel-level mapping; it doesn’t copy the files or make them part of drive A. The mount configuration will disappear when you replace the OS, so you’ll need to recreate it afterward.
The bind mount itself won’t survive the reinstall because it has to be recreated at boot, usually through the new system’s mount configuration. That affects how the folder is accessed, not the folder’s contents on drive B. Still, verify the target drive and partitions carefully because choosing the wrong one in the installer would erase it.
Before installing, double-check the installer’s partition and formatting selections. Make sure drive B and its data partition are not selected for formatting or deletion.