尝试安装 openssl 包时出现以下错误

Question

我正在尝试安装新包并出现以下错误，我该如何修复？

# sudo apt-get install openssl
Reading package lists... Error!
E: Write error - write (28: No space left on device)
E: IO Error saving source cache
E: The package lists or status file could not be parsed or opened.

输出如下df --si：

Filesystem      Size  Used Avail Use% Mounted on
udev            238M     0  238M   0% /dev
tmpfs            52M  4.0M   48M   8% /run
/dev/vda1       5.2G  5.2G     0 100% /
tmpfs           256M     0  256M   0% /dev/shm
tmpfs           5.3M     0  5.3M   0% /run/lock
tmpfs           256M     0  256M   0% /sys/fs/cgroup
tmpfs            52M     0   52M   0% /run/user/0