HP SIM issue after P to V, Event ID 3

[Vince Kwok]

After virtualizing our HP SIM server, version 5.3 (from HP 380 G3 server to VMware ESXi 3.5 platform), our HP SIM server keeps having the issue of "lost connection to database". I have tried P to V twice, I gotta the same issue. Everything seems fine at the beginning, but HP SIM stops working after around 30 minutes of booting up. Rebooting can fix it temporarily, but it stops again after around 30 minutes.
Please help me on this. Thank you in advance.

Event ID:3

Lost connection to database, exception: java.sql.SQLException: I/O Error: Connection reset by peer: socket write error SQL=select DeviceKey2 from device_associations where DeviceKey1=1225 AND (AssociationTypeNumber like 'MgmtProcToServer%')