A system administrator has an application that has the data in volume group appvg. Which of the following commands will back up the contents of appvg to the tape in /dev/rmt0 and check for any read errors？（）

单项选择题ApSeriesserverisbeingusedasafileserverandalldataisstoredonanon-rootvolumegroupandresidesonmountedfilesystems.Whichofthefollowingcommandsprovidesthequickestwaytobackupallofthedataandfilesystemdefinitions？（）

A.tar
B.cpio
C.savefs
D.savevg

单项选择题Acompanyusesrawlogicalvolumes.Whichcommandcanbeusedtobackupthedataintherawlogicalvolumestoatape？（）

A.dd
B.tar
C.cpio
D.mksysb

单项选择题Asystemadministratorisattemptingtorestoresomefilesfromabackuptape.Therestorefailed.Thesystemadministratorsuspectstheblocksizeofthetapedriveisincorrect.Whichofthefollowingcommandscanbeusedtodeterminetheblocksizeofthebackuptape？（）

A.dd
B.tar
C.cpio
D.restore

单项选择题Asystemadministratorwantstoautomaticallyejectthebackuptapeeachnightafterthebackupiscomplete.Whichcommandcanbeusedtoejectthetape？（）

A.tar
B.tctl
C.rmdev
D.backup

单项选择题Therootvgdiskonasystemfailedandwasreplaced.Thesystemwasrestoredusingthelatestmksysb.However，nofilesinthe homefilesystemwererestored.Whatisthelikelycauseofthisproblem？（）

A.The new drive is too small to hold the entire rootvg
B.The /home filesystem was not mounted during creation of the mksysb
C.The /home stanza in the bosinst.data contained an entry ’restore=no’
D.The /home filesystem was NFS exported to another system during creation of the mksysb