I have 8 drives in the Proliant G7, and when under disk load there is a clicking sound from one of them.
There are NO SMART ERROR MESSAGES.
It is running ESXi, which shows warnings about i/o latency increasing (sometimes to multiple seconds) on the HP internal SCSI Disk (this is just the logical disk), but does not provide drive specific information.
I do have the HP custom ESXi 6.0 build running, but there is no error on the SMART flags for any of the drives.
I can audibly hear the drive clicking, and I have a spare ready, but I do not know which drive to replace.