There are no standardized commands for backing up a Linux system. Backup methods can range from dd to RAID to one of various backup utilities.
last, chage, chsh, lsof, chown, chmod, useradd, userdel, newusers.
utilities is nothing but predefined commands in linux
tell me about device management in Linux?
Innumerable. Remember that any program on Linux can be launched from the command line, so there are as many commands as there are programs.
TAR
There is no standardized backup utility for Linux, thus you are not limited to any particular program. Depending on your needs, a backup could range anywhere from regular syncing with a remote server of certain files to a complete bit by bit backup with dd.
ls
You can copy and backup any file in Linux, even if they are open. However, if the file is being edited, this is generally a bad idea, since the backup will not reflect any recent changes after they are saved.
Linux command "dump" backup 0 means to store everything or full backup.
Yes. Just about everything to do with Linux on the command line is case sensitive, including commands and file names.
Oracle 10g's commands are internal; they have nothing to do with what platform it is running on.
There is none. For starters, you have it backwards, DOS actually copied most of its commands from Unix (The rest came from CP/M.), which Linux is inspired by. Commands like "cd" and "dir" were Unix commands long before DOS even existed.