Examine the output of the command:
Issubsys -am
devices
freezer
net_cls
perf_event
hugetlb
cpuset, cpu, memory
/cgroup/A
cpuacct
/cgroup/cpuacct
blkio
/cgroup/B
Now the Issubsys command is executed and new output is generated: ssubsys -am
devices
perf_event
hugetlb
cpuset, cpu, memory
/cgroup/A
cpuacct
/cgroup/cpuacct freezer, net_cls cgroup/C blkio
/cgroup/B
Which command or sequence of commands is correct?
A.
mkdir -p /cgroup/C; mount -t cgroup -o freezer C /cgroup/C;
mount -t cgroup -o remount, freezer, net_cls C /cgroup/C
B.
mkdir -p /cgroup/C; mount -o freezer, net_cls cgroup /cgroup/C
C.
mkdir -p /cgroup/C; mount -t cgroup -o freezer freezer /cgroup/C;
mount -tcgroup -o net_cls net_cls /cgroup/C
D.
mkdir -p /cgroup/C, mount -t cgroup -o freezer, net_cls /cgroup/c
some help on this one
B
[root@ole6 ~]# mount -t cgroup -o freezer,net_cls cgroup /cgroup/C
[root@ole6 ~]# lssubsys -ma
cpuset
cpu
cpuacct
memory
devices
blkio
perf_event
hugetlb
freezer,net_cls /cgroup/C
A is correct, 100% sure
[root@www ~]# mkdir /cgroup/C
[root@www ~]# mount -t cgroup -o freezer C /cgroup/C
[root@www ~]# mount -t cgroup -o remount,freezer,net_cls C /cgroup/C
[root@www ~]# lssubsys -ma
cpuset
cpu
cpuacct
memory
devices
blkio
perf_event
hugetlb
freezer,net_cls /cgroup/C
[root@www ~]#
[root@www ~]#
[root@www ~]# umount /cgroup/C
[root@www ~]# mount -o freezer,net_cls cgroup /cgroup/C
mount: you must specify the filesystem type
[root@www ~]#
[root@www ~]# mount -t cgroup -o freezer freezer /cgroup/C
[root@www ~]# mount -t cgroup -o net_cls net_cls /cgroup/C
[root@www ~]# lssubsys -ma
cpuset
cpu
cpuacct
memory
devices
blkio
perf_event
hugetlb
freezer /cgroup/C
net_cls /cgroup/C
[root@www ~]#
[root@www ~]#
[root@www ~]# umount /cgroup/C
[root@www ~]# umount /cgroup/C
[root@www ~]# mount -t cgroup -o freezer,net_cls /cgroup/C
Usage: mount -V : print version
mount -h : print this help
mount : list mounted filesystems
mount -l : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere’.
Details found in /etc/fstab may be omitted.
mount -a [-t|-O] … : mount all stuff from /etc/fstab
mount device : mount device at the known place
mount directory : mount known device here
mount -t type dev dir : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
mount –bind olddir newdir
or move a subtree:
mount –move olddir newdir
One can change the type of mount containing the directory dir:
mount –make-shared dir
mount –make-slave dir
mount –make-private dir
mount –make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
mount –make-rshared dir
mount –make-rslave dir
mount –make-rprivate dir
mount –make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using -L label or by uuid, using -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say man 8 mount .
[root@www ~]#