More Linux Tips

- Detailed info about system: Actually these are kernel messages and are stored as logs in /bin/dmesg.
$dmesg

- Determining runlevel {Shows previous & current runlevel}
$runlevel
0->Halt 1->Single User Mode
2-> Multiuser w/o NFS 3-> Full Multiuser 6-> Reboot

To modify init level-> /etc/inittab

- To switch runlevels, use init command.
$init 3

- Difference between Paging and Swapping
Paging refers to movement of pages to frames on the disk. It's a considerably cheaper operation. Swapping means to move entire address space of a process to disk. This is very expensive operation and happens when a process sleeps or when thrashing occurs.