On shared storage, files disappear from ext4 read-only file system?

Issue

• Ext4 File system configured on a SAN that is attached to two machines. The first machine is a RHEL 6 server that has rw(read-write) access. The second server is RHEL 5 that has ro(read-only) access. With time the files disappear from the RHEL 5 server ro file system, but they are still on the RHEL 6 rw file system.

• This is been done to reduce the Ethernet network load for copying the files and to reduce the amount of SAN space needed for this. Should this work, do you have a different suggestion?

• There is shared disk where ext4 filesystem created and mounted it on two servers out of which one is RHEL 6 and other is RHEL 5. Need to mount and use the shared disk with ext4 filesystem as read only from RHEL 5 system and read-write from RHEL 6 system. Now, only able to use the filesystem on one server at a time. Any idea on how to do it on both nodes?