i am running Ubuntu 11.04 instance for my Web Server on AWS cloud, now i am getting there is no disk space in / partition of my server. df -ah say this

Filesystem            Size  Used Avail Use% Mounted on
/dev/xvda1            7.9G  7.8G   97M  99% /
proc                     0     0     0   -  /proc
none                     0     0     0   -  /sys
fusectl                  0     0     0   -  /sys/fs/fuse/connections
none                     0     0     0   -  /sys/kernel/debug
none                     0     0     0   -  /sys/kernel/security
none                  3.7G  112K  3.7G   1% /dev
none                     0     0     0   -  /dev/pts
none                  3.7G     0  3.7G   0% /dev/shm
none                  3.7G   80K  3.7G   1% /var/run
none                  3.7G     0  3.7G   0% /var/lock
/dev/xvdb             414G   16G  377G   4% /mnt

Now i have Tried these thing for getting some extra space on / partition

• Clean up All Log files for Apache.
• Removed all unnecessary files from server.
• Home directory Cleanup.

But Still I am not getting enough space. This Instance type is m1.large with 8GB EBS. Now i am getting i have enough disk space in /dev/xvdb.

Is there a way i can allocate some diskspace to / from /dev/xvdb or Any other Ways. Please suggest me the possible solution for this.Is it possible to use the same /dev/xvdb partition with another instance.