Slow rescan on Melco N1A

[jacobacci]

I am running fairly large music libraries with MinimServer on
- Synology DS1815+ (11.5TB library)
- Synology DS1019+ (11.5TB library)
- Melco N1A 2EX (two 3TB HDs in RAID0) (4.5TB library)
I am seeing very different rescan times on the NAS' and on the Melco:
Melco: initial scan: 34 min, rescan 32 min
DS1019+: initial scan around 45 min (from memory), rescan around 1 min

Why would the rescan on the Melco take almost the same time as the initial scan, while on the NAS' it is very quick.

P.S. Is there any way I can launch a full initial scan with MinimServer? I would like to redo a clean set of measurements once more.