当我通过齿轮或关闭按钮右上方菜单上的命令关闭系统时，此过程会卡住。当我使用 [ESC] 查看终端时，我发现 USB 驱动器未被卸载。
当我通过命令重新启动或关闭系统时从终端，
sudo shutdown -r [now]
sudo shutdown -P [now]
它运行正常. 除了关机命令之外的菜单项还有什么？
安装输出：
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=4022672k,nr_inodes=1005668,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=806868k,mode=755)
/dev/mapper/ubuntu--vg-root on / type ext4 (rw,relatime,errors=remount-ro,data=ordered)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (rw,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,clone_children)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=23,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/sdc1 on /media/conte/lw640 type ext4 (rw,nosuid,nodev,relatime,data=ordered)
/dev/sdb1 on /media/conte/lw500 type ext4 (rw,nosuid,nodev,relatime,data=ordered)
/dev/sda1 on /boot type ext2 (rw,relatime,stripe=4)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,relatime)
cgmfs on /run/cgmanager/fs type tmpfs (rw,relatime,size=100k,mode=755)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=806868k,mode=700,uid=1000,gid=1000)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
有问题的驱动器是 /dev/sdb1
smartctl 的输出：
smartctl 6.4 2014-10-07 r4002 [x86_64-linux-3.19.0-30-generic] (local build)
Copyright (C) 2002-14, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Vendor: PI-239
Product: USB 2.0 Drive
Revision: 1.08
User Capacity: 500.107.862.016 bytes [500 GB]
Logical block size: 512 bytes
scsiModePageOffset: response length too short, resp_len=4 offset=4 bd_len=0
scsiModePageOffset: response length too short, resp_len=4 offset=4 bd_len=0
>> Terminate command early due to bad response to IEC mode page
A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.
这个问题仅存在了几天，在此期间我没有对系统进行任何改动。
答案1
问题解决了。我已在 fstab 中删除了条目“x-gvfs-show”。
老的：
UUID=e6e1e5b3-5395-4145-9504-54bb926aab76 /media/conte/lw500 auto nosuid,nodev,nofail,x-gvfs-show 0 0
新的：
UUID=e6e1e5b3-5395-4145-9504-54bb926aab76 /media/conte/lw500 auto nosuid,nodev,nofail 0 0
现在，重启和关机都可以正常使用了。