EMD upload error:

Oracle agent can throw an EMD error for disk full.
Basically it means that the Disk on which agent is showing used percentage more than 98%

Error Seen

EMD upload error: Upload was successful but collections currently disabled - disk full 

Reason for the above error is that the EMD disk system shows used percent more than 98%.The agent requires the space for upload files is 98% by default. The agent collections will stop when the space on the disk is used beyond the default.
Solution is to release the space on the disk.
Also update the parameter UploadMaxDiscUsedPct=99 & UploadMaxDiskUsedPctFloor=99 in the emd.properties file

./emctl stop agent
Oracle Enterprise Manager 10g Release 5 Grid Control 10.2.0.5.0.
Copyright (c) 1996, 2009 Oracle Corporation.  All rights reserved.
The Oracleagent10gAgent service is stopping.....
The Oracleagent10gAgent service was stopped successfully.

./emctl start agent
Oracle Enterprise Manager 10g Release 5 Grid Control 10.2.0.5.0.
Copyright (c) 1996, 2009 Oracle Corporation.  All rights reserved.
The Oracleagent10gAgent service is starting..............
The Oracleagent10gAgent service was started successfully.

./emctl upload agent
Oracle Enterprise Manager 10g Release 5 Grid Control 10.2.0.5.0.
Copyright (c) 1996, 2009 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
EMD upload completed successfully