Disk space monitoring and snmp issues

I'm currently trying to figure out now to get around two rather severe problems.

1. We currently have alarms set on our diskspace monitoring to alert us at 90%, this part is working fine so far. The problem we're experiencing is that we on occasion have disks that fill up and aren't out responsibility to clean out or we may need guidance on what needs to be compressed, etc...

I our current setup the monitoring system shows a list of servers over the 90% threshold and updates the amount of free space remaining after each system check. Is there any way to get opmanager to update the amount listed on the alarms other that have the noc guys clear the alarm manually so it comes back with new amount. So far the only thing I can think of as a safe guard is to create a second disk space monitor so I can set another alarm at 95 or 98%.

2. Snmp stopped functioning correctly on one of our linux servers, although the process was still running. Our current monitoring system sent out alarms as it could no longer see the processes and resources it was monitoring. Opmanager on the other hand didn't notify as to any problem. This could have led to issues such as disk unknowingly filling up, etc...

Any suggestions as to how we get alarms over failures like these?

Thanks,

Colin