Will shrinking a partition destroy all data?

Solution 1:

In theory you will not lose data.

In practice over the years I have used built-in tools on Windows, gparted on Linux, and other third party utilities to shrink or resize partitions on various operating systems and everything has gone well with no data loss.

But sometimes things happen, filesystems look fine but might have some odd corruption as power outages happen, structures get updated over the years as software changes slightly and sometimes the shrinking software just chokes, gives up and leaves your disk in a state that is, to put it politely, Not Good.

I've even started shrinking a disk in Windows, left it for half an hour, realised I made a critical mistake, tried to cancel, then hard powered off the machine. When powered back on it carried on as if nothing at all had happened and was 100% fine. That I got lucky doesn't make doing this "safe". I was expecting the disk to be toast.

All that said you should be able to shrink a disk without losing everything, that doesn't mean you shouldn't prepare for the worst.

Make sure your backups are good, and know what your strategy for reinstalling is if the worst happens.