单项选择题 Whatcommandshouldasystemadministratorrunafterusinganeditortocreatethe/etc/tunables/nextbootfile？（）

单项选择题 Whatstanzafiledoesasystemadministratorviewtodeterminewhatkernel-tuningparameterchangesweremadewhenthesystemwaslastbooted？（）

单项选择题 An administrator attempted to run a sar -u report and received the following error：   sar： 0551-201 Cannot open /var/adm/sa/sa07.   Which of the following should be scheduled in adm’s crontab to obtain sar reports？（）