In which directory are the basic Linux commands such as gzip， gunzip and zcat installed？（）

单项选择题Asystemadministratorhasanapplicationthathasthedatainvolumegroupappvg.Whichofthefollowingcommandswillbackupthecontentsofappvgtothetapein dev rmt0andcheckforanyreaderrors？（）

A.savevg -mf /dev/rmt0 appvg
B.savevg -cvf /dev/rmt0 appvg
C.savevg -xvf /dev/rmt0 appvg
D.savevg -f /dev/rmt0 -V appvg

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