(Original query accidentally overwritten, but the subject tells it all.)
The first thing to do with an issue like this is to isolate the problem.
Try shutting down all the computers on your network and seeing if the drive goes to sleep. If it does, than your issue is related to one of the computers and not the drive - most likely there is software interacting with the drive (or malware etc.). If this is the case you will need to determine first what computer is causing the issue (turn them on 1 at a time and see which one is preventing it from sleeping) and than what software is causing it (check your processes list, etc.). If its software you want/need/use you will have to figure out what changed- it’s possible an update of some sort triggered the behavior (this is most common with anti-virus software, etc.) - if it is something unknown/you don’t want/harmful remove the sotware and the issue should go away.
If none of this solves your issue, it could be a problem with your router. Try disconnecting the drive from the router and seeing if it solves the issue. If so, than similar to the above with your computer you will need to determine what changed to cause the behavior to occur.
If the drive continues to stay awake than the issue may be with the drive. I would back up everything on the drive and try a factory restore to see if that solves the issue, but there may be a few things people can suggest prior to doing that.
Right… Something did change and may be better documented here and not just to erase this thread. It’s in case anyone else has the same idea and notices the same thing I did.
I conducted an experiment to see if NetBIOS browsing could be made more better but in the heat of everything I did get distracted by some other real life event and forgot to copy the original file back. (aka. Restore the settings back to the original.)
I had added wins support = yes to /etc/samba/smb-global.conf after (wisely) making a copy of the original. I had forgotten to copy the original file back over the modified file once the experiment was completed to return everything back to its original state and during my investigation of the “drive not sleeping” problem noticed the date and time the configuration was altered tallied with the time the NAS had stopped sleeping. (aka… “1 + 1 = 2!”)
The reason the drive never went to sleep is because samba began maintaining a file names /var/lib/samba/wins.dat and this is not stored within in the NAS’s ram-disk. So every time Samba altered the file the disc got touched.
Just in case anyone else spots this while rooting through Samba’s instructions and starts wondering, quite correctly, . . . “Hmmm… WINS is a whole heap better then simple NetBIOS browsing. Why not try use Samba’s built-in WINS service instead of NetBIOS browsing.” The answer is . . . “Yes you can use WINS and it is better than simply NetBIOS browsing but the NAS will never go to sleep with Samba’s WINS support enabled.”
Myron wrote:
Right… Something did change and may be better documented here and not just to erase this thread. It’s in case anyone else has the same idea and notices the same thing I did.
I conducted an experiment to see if NetBIOS browsing could be made more better but in the heat of everything I did get distracted by some other real life event and forgot to copy the original file back. (aka. Restore the settings back to the original.)
I had added
wins support = yesto/etc/samba/smb-global.confafter (wisely) making a copy of the original. I had forgotten to copy the original file back over the modified file once the experiment was completed to return everything back to its original state and during my investigation of the “drive not sleeping” problem noticed the date and time the configuration was altered tallied with the time the NAS had stopped sleeping. (aka… “1 + 1 = 2!”)
The reason the drive never went to sleep is because samba began maintaining a file names
/var/lib/samba/wins.datand this is not stored within in the NAS’s ram-disk. So every time Samba altered the file the disc got touched.
Just in case anyone else spots this while rooting through Samba’s instructions and starts wondering, quite correctly, . . . “Hmmm… WINS is a whole heap better then simple NetBIOS browsing. Why not try use Samba’s built-in WINS service instead of NetBIOS browsing.” The answer is . . . “Yes you can use WINS and it is better than simply NetBIOS browsing but the NAS will never go to sleep with Samba’s WINS support enabled.”
ahhhh ok - you never mentioned any of that in your original post. I had assumed you hadn’t been tinkering around via SSH 
I tinkered ever so slightly. Just didn’t realise Samba would be constantly touching wins.dat. My MBL is now sleeping like a well behaved baby. Pity. The WINS service is a whole heap better than simple NetBIOS name broadcasts over the network.
I guess what I could try is enable wins and then disable it to create wins.dat. Copy the file to /ver/log and then where wins.dat is supposed to be, create a symbolic link to the wins.dat in the ramdisk? I guess there is no harm in trying as long as a back-up is taken of everything changed and a exact change log maintained?
Just a thought. Chances are I won’t even try to do this. 
