VM restarted without prior notice - Big data loss

Hi,

I just discovered that my VM has been restarted without prior notice today. After logging in, I found all the data in /mnt disappear.

This is the second time I lost all the data in Microsoft Virtual Machines.

root@fscs1:/home/xx# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        29G  1.8G   26G   7% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
udev            828M  8.0K  828M   1% /dev
tmpfs           168M  364K  168M   1% /run
none            5.0M     0  5.0M   0% /run/lock
none            840M     0  840M   0% /run/shm
none            100M     0  100M   0% /run/user
/dev/sdb1        69G   52M   66G   1% /mnt

The /dev/sdb1 contains nothing at the moment. I stored a lot of data there yesterday.

Microsoft Virtual Machines is extremely unstable and alpha quality to me

I appreciate if Microsoft can give me an explanation on what happened.

Regards,