$ sudo -iu cyrussudo: unable to change directory to /srv/cyrus: Permission deniedsudo: unable to execute /bin/zsh: Permission deniedI don't understand why I would get permission denied for /bin/zsh at all:$ stat /bin/zsh  File: `/bin/zsh' -> `/etc/alternatives/zsh'  Size: 21          Blocks: 0          IO Block: 4096   symbolic linkDevice: ceh/206d    Inode: 49686869    Links: 1Access: (0777/lrwxrwxrwx)  Uid: (    0/    root)   Gid: (    0/    root)Access: 2014-05-02 22:19:33.464671249 +0800Modify: 2014-05-02 22:12:21.447725196 +0800Change: 2014-05-02 22:12:21.452724872 +0800 Birth: -and /srv/cyrus:$ stat /srv/cyrus/  File: `/srv/cyrus/'  Size: 4096        Blocks: 8          IO Block: 4096   directoryDevice: ceh/206d    Inode: 50467467    Links: 3Access: (0750/drwxr-x---)  Uid: ( 1002/  cyrus)   Gid: ( 1002/  cyrus)Access: 2014-05-02 22:05:57.702641011 +0800Modify: 2014-05-02 22:05:58.135612918 +0800Change: 2014-05-02 22:11:39.313461373 +0800 Birth: -How do I debug this type of problem?
Can't simulate initial login using sudo
permissions;sudo;users