When checked the sent file, found the following messages in every server's log.
Insufficient privilege level
Customer use a user with admin authority that is not "root user".
In the old BMC verison (prior to 2.06), when root user is disabled, non-root use can not get normal logs although the user have admin privilege.
Upgrade the BMC verions to latest one, and meanwhile upgrade BIOS version. after upgrade, we can collect normal server logs.