You are the administrator of a Linux system that provides file and print services to over 100 clients in your company. The system uses several fast SSD hard disks and has a Xeon E5 processor with 16GB of RAM. Since its installation, you have installed database software that is used by only a few users. Unfortunately, you have rarely monitored and documented performance information of this system in the past. Recently, users complain that the performance of the server is very poor. What commands could you use to narrow down the problem? Are there any other troubleshooting methods that might be useful when solving this problem?