View source for Category:Linux troubleshooting

==System information==
 $ dmesg
 $ iostat
 $ vmstat  # to quickly monitor CPU, memory, and I/O usage and decide which is the bottleneck

 $ ps -ef | egrep '^root ' | gawk '{print $2}'  # method 1
 $ pgrep -u root                                # method 2

 $ cat /proc/cpuinfo
 $ cat /proc/partitions
 $ cat /proc/meminfo
 $ cat /proc/sys/vm/swappiness  # number from 0 - 100; the higher the number the more the system will swap
 $ cat /proc/interrupts   # inspect your /proc/interrupts file for multiple devices having the same interrupt

 $ lspci # lists all PCI buses and devices connected to them
 $ lsusb # lists all USB buses and any connected USB devices
 $ lshal # lists all devices the hardware abstraction layer (HAL) knows about (should be most hardware on your system)
 $ lshw  # lists hardware on your system, including maker, type, and where it is connected

 $ uname -a  # system architecture
 $ cat /etc/issue                   # Display distribution and version (on some distros)
 $ lsb_release -a
 $ grep ^VERSION /etc/SuSE-release  # To see which SuSE Linux version you are using
 $ cat /etc/mandriva-release        # To see which Mandriva Linux version you are using
 $ dmesg | head                     # full version info.
 $ cat /proc/version                # full version info.
 $ cat /etc/issue                   # display Linux distribution
 $ pstree
 $ lsof | grep TCP                  # list open files
 $ lsof |grep ' root ' |awk '{print $NF}' |sort|uniq|wc -l # list number of open files for a user
 $ lsof -i :22 # list all connections via port 22 (i.e., ssh)
 $ strace 'command'                 # trace system calls and signals for a given command

 $ getconf     # print system configuration variables
 $ getconfig   # get configuration information for the Xorg server
 $ systool     # view system device information by bus, class, and topology
 $ dmidecode   # DMI table decoder
 $ dmidecode -s system-product-name
 $ dmidecode -s system-manufacturer
 $ biosdecode  # BIOS information decoder
 $ bind -P     # print keyboard bindings

 $ acpi -t     # Check current battery charge system temperature (package might not be installed by default)
 $ finger -l   # Display information about all system users

 $ cat /proc/scsi/scsi
   WDC WD2000JD-22H Rev: 08.0
   SATA-I, 200 GB, 150 MB/s, 8 MB Cache, 7200 RPM

===See also===
*[http://ezix.org/project/wiki/HardwareLiSter lshw] (Hardware Lister)
*[[hdparm]] &mdash; get/set hard disk parameters