A system administrator has a server that is performing poorly. The vmstat command identifies that high CPU usage is the problem. Which of the following commands can be used to identify the eight most active processes running on the server？（）

单项选择题Asystemadministratorisunabletounmountafilesystem.Whichistheappropriatecommandtodeterminewhoorwhatisaccessingthefilesystem？（）

A.who /filesystem
B.lsfs /filesystem
C.fuser /filesystem
D.umount -f /filesystem

单项选择题Asystemadministratorwantstoconfigureasystemsothatallnewuserswillbeputintothedatabasegroupbydefault.Howwouldthisbeaccomplished？（）

A.remove all other groups from the system
B.run the command mkuser -default "GROUP=database"
C.change the default group in /usr/lib/security/mkuser.default
D.edit /etc/security/group to move all users to the database stanza

单项选择题Asystemadministratorwouldliketomodifythesystemdefaultusercharacteristicssothateachnewuserwillnowbeassigned（bydefault）thecshshellratherthanthekshshell.Whichofthefollowingactionsshouldbeperformed？（）

A.Run the command chlogin -shell "csh"
B.Run the command mkuser -default "SHELL=csh"
C.Edit /etc/passwd and change all "ksh" entries to "csh"
D.Modify the contents of /usr/lib/security/mkuser.default file

单项选择题Forsecurityreasons，anadministratorisaskedtomodifythesystemtopreventsomeonefromleavingaterminalloggedin.Toenableafiveminutetimeoutforallusers，whatwouldneedtobedonetoaccomplishthistask？（）

A.Add the following line to /etc/environment：  TMOUT=300
B.Add the following lines to /.profile  TMOUT=5  export TMOUT
C.Execute the following command：  chuser -u ALL -a TIMEOUT=5M
D.Execute the following command：  chsec -u ALL -a TIMEOUT=600

单项选择题WhichactionchangesthedefaulteditorforALLusersonthesystemfromvitoeditofthefollowing？（）

A.Issue the command：  export EDITOR=/usr/bin/edit
B.Modify /.profile and change the EDITOR variable to /usr/bin/edit
C.Modify /etc/environment and add  EDITOR=/usr/bin/edit  export EDITOR
D.Modify /etc/security/defaults and change the EDITOR value to /usr/bin/edit