diff --git a/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat b/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
index e740bed52..340dfc027 100644
--- a/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
+++ b/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
@@ -2,7 +2,7 @@ start:reg_linux_diskfull_installation_flat
 os:Linux
 
 cmd:if ping -c 1 $$SN > /dev/null;then rpower $$SN off > /dev/null;fi
-cmd:MINIISO=NUll;if [[ "__GETNODEATTR($$CN,os)__" =~ "ubuntu" ]] && [[ "__GETNODEATTR($$CN,arch)__" =~ "ppc64le" ]];then mkdir /tmp/iso; mount -o loop $$MINIISO /tmp/iso ;  mkdir -p  /install/__GETNODEATTR($$CN,os)__/__GETNODEATTR($$CN,arch)__/install/netboot; cp  /tmp/iso/install/initrd.gz  /install/__GETNODEATTR($$CN,os)__/__GETNODEATTR($$CN,arch)__/install/netboot;umount /tmp/iso; rmdir /tmp/iso; fi
+cmd:MINIISO=NUll;if [[ "__GETNODEATTR($$CN,os)__" =~ "ubuntu" ]] && [[ "__GETNODEATTR($$CN,arch)__" =~ "ppc64" ]];then mkdir /tmp/iso; mount -o loop $$MINIISO /tmp/iso ;  mkdir -p  /install/__GETNODEATTR($$CN,os)__/__GETNODEATTR($$CN,arch)__/install/netboot; cp  /tmp/iso/install/initrd.gz  /install/__GETNODEATTR($$CN,os)__/__GETNODEATTR($$CN,arch)__/install/netboot;umount /tmp/iso; rmdir /tmp/iso; fi
 check:rc==0
 
 cmd:chdef -t node -o $$CN servicenode= monserver=$$MN nfsserver=$$MN tftpserver=$$MN  xcatmaster=$$MN