hi nixcraft,

thanks for ur reply.

after this pbm happend, 1st step i did is using "single user" to boot the system.while the time we are entering into single user mode, its easily enable the swap space.means "Enabling Swap Space [ok] ".but, if i am trying to run into multi user mode say runlevel 3, it just hangs up.
i couldn't able to find out the reason. my /etc/fstab file is edited properly.if u need i can paste into this forum.give me any solution for this.b'cz i am trying to find out this answer from past 1 & half year.

thanks,
aaru