Redhat - quick reference commands

/boot/grub/grub.conf (boot prompt)

/var/log/dmesg (kernel messgages)

/etc/inittab (id:5:initdefault)

/etc/rc.d/rc.sysinit (system initialization)

ls -ltr /etc/rc.d/init.d (scripts initizliae in /etc/inittab)

lsmod | grep oracle (kernel module for oracle)

/proc:  is a virtual filesystem that provides detailed information about the kernel, hardware and running processes.  Some interesting /proc entries:

/proc/PID

/proc/cpuinfo

/proc/partitions

/proc/meminfo

/proc/dmstat

/proc/swaps

/proc/mounts

/proc/net

/proc/sys/kernel/hostname

/proc/sys/vm/swappiness (indicate how aggressive memory will be swapped out to the sap devices)

/etc/sysctl.conf  , sysctl –a (to view kernel parameters) –w (to set) –p (to sync)

netstat –tanp

to be continued...