[Samba] Windows explorer pop-up descriptions: unfair to Samba

[Chris Stankevitz]

Hello,

I would like to get this question answered in support of a decision
about whether or not to move some large shares from Windows Server to
Samba.

Windows Explorer has a feature called "Show pop-up description for
folder and desktop items", which I will call SPD.  SPD, which is
enabled by default, shows a folder's contents and size when you hover
your mouse cursor over it.  It even works when you are just moving
your mouse cursor from the bottom of your screen to the top and just
"happen" to have it glide across a directory or two.

Explorer accomplishes SPD by opening the directory and looking at its
contents in the background.  When the entire contents (including sub
directories) have been traversed, it creates a pop-up near the
directory icon.  When browsing network shares, this can generate a lot
of SMB traffic (depending on directory tree size).  This can also take
a long time to complete.  You can use wireshark to watch tens of
thousands of smbd_dirptr_get_entry messages generated by this activity
in large shares.

Question: What does SPD do if the user "hovered" his cursor over a
directory, but only momentarily, before moving this mouse elsewhere on
the screen (on a network share)?

Answer when connected to a samba server: When the user momentarily
hovered his cursor over the directory, explorer begins recursing the
directory structure,s ending and receiving SMB commands.  Even after
the user moves his mouse away, this recursion continues and can take
minutes to complete (imagine a very large directory structure).
Frighteningly, sometimes (but not always), Explorer.exe locks up
waiting for this process to complete.  During the "lock up", the user
experiences an hourglass/spinning_blue_wheel and the explorer window
does not refresh.

Question: Why does it seem like this undesirable "lock up" happens
only when connected to a Samba server and not when connected to a
genuine Windows Server?

Answer: ?

Question: Why do users report relief after disabling "Show pop-up
description for folder and desktop items" but subsequently and
periodically report other "lock ups" that presumably are not due to
"Show pop-up description for folder and desktop items"?

Answer: ? (presumably there are other things besides SPD that do not
play nice with Samba but do play nice with Windows Server... maybe
virus scanner?)

Thank you,

Chris