在ubuntu系统下卸载vsftpd出错，具体内容是：
$ sudo apt remove vsftpd
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
vsftpd
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 352 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 215847 files and directories currently installed.)
Removing vsftpd (3.0.3-8) ...
dpkg: error processing package vsftpd (--remove):
subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg received a segmentation fault.
解决：
# 手动删除用户ftp
sudo deluser --system ftp
# 删除vsftpd
sudo apt remove vsftpd