The problem has been solved. Move snap packages to another location/directory
on centos7, the first time snap application can be successfully launched, but the second time it can not be started, the error message is below. Any ideas?
$ snap run hello
cannot find mount entry for snap core revision 7713
by the way, when i installed snapd, i executed the following commands
# ln -s /var/lib /usr/var/lib
$ snap version
snap 2.39.2-1.el7
snapd 2.39.2-1.el7
series 16
centos 7
kernel 3.10.0-1062.1.1.el7.x86_64
$ snap list
Name Version Rev Tracking Publisher Notes
core 16-2.41 7713 stable canonical✓ core
core18 20190904 1144 stable canonical✓ base
hello 2.10 38 stable canonical✓ -
# df -h |grep snap
/dev/loop0 128K 128K 0 100% /usr/var/lib/snapd/snap/hello/38
/dev/loop1 90M 90M 0 100% /usr/var/lib/snapd/snap/core/7713
/dev/loop2 55M 55M 0 100% /usr/var/lib/snapd/snap/core18/1144
# systemctl status snapd
● snapd.service - Snappy daemon
Loaded: loaded (/usr/lib/systemd/system/snapd.service; disabled; vendor preset: disabled)
Drop-In: /etc/systemd/system/snapd.service.d
└─override.conf
Active: active (running) since 五 2019-09-27 07:21:28 CST; 38min ago
Main PID: 21284 (snapd)
Tasks: 57
Memory: 28.3M
CGroup: /system.slice/snapd.service
└─21284 /usr/libexec/snapd/snapd
9月 27 07:21:28 xeon-e5 systemd[1]: Starting Snappy daemon...
9月 27 07:21:28 xeon-e5 snapd[21284]: AppArmor status: apparmor not enabled
9月 27 07:21:28 xeon-e5 snapd[21284]: daemon.go:379: started snapd/2.39.2-1.el7 (series 16; classic; devmode) centos/7 (amd64) linux/3.10.0-1062.1.1.el7.x86_6.
9月 27 07:21:28 xeon-e5 systemd[1]: Started Snappy daemon.