Re: opportunistic locking on Isilon and windows 7 clients

Disabling oplocks does not force clients to use SMB1 and I am unaware of disabling oplocks causing problems with Offline files (you might be thinking of change notify because if you turn that off on SMB2 clients, it does break offline files).  Oplocks are a tuning mechanism and are turned off based on customer application requirements.  Microsoft has a very good writeup on oplocks for SMB1 and SMB2 here:

https://blogs.msdn.com/b/openspecification/archive/2009/05/22/client-caching-features-oplock-

vs-lease.aspx?Redirected=true

Also, when it comes to oplocks, Microsoft Excel seems to be the biggest culprit in having problems with them.  Its generally recommended to turn oplocks off on the share when troubleshooting "locking" issues with Microsoft Excel.  In addition to doing that, we also recommend the following when dealing with Excel on a NAS device:

1.    Confirm that the hotfix for Office 2010 in the link below has been applied to the test client.

a.    http://support.microsoft.com/kb/2597142/en-us

2.    Confirm that the latest Office 2010 Cumulative update has been applied to the test client.

a.    http://support.microsoft.com/kb/2855357

3.    Disable the Preview Pane in Windows explorer (Windows 7 & 2008) and Excel using the steps below:

a.    For windows explorer (Windows 7 & 2008)

i.    Right click on the Start Button.

ii.    Click 'Open Windows Explorer'

iii.    At the top left click Organize  Layout

iv.    Uncheck Details Pane and Preview Pane

v.    On a Windows menu, click on Tools  Folder Options.  In the box that opens up, click on the View tab.  Scroll down the list to “Show pop-up description for folder and desktop items” and clear the checkbox and then click OK.

b.    For Excel/Word

i.    Click File  Open

ii.    Click Organize  Layout

iii.    Uncheck 'Details Pane' and 'Preview Pane'

iv.    On a Windows menu, click on Tools  Folder Options.  In the box that opens up, click on the View tab.  Scroll down the list to “Show pop-up description for folder and desktop items” and clear the checkbox and then click OK.

One question though: is there any way to measure the amount of bandwidth you're (possibly) saving by having oplocks on? We're contemplating turning oplocks off for a large set of departmental shares and don't want to get swamped by SMB requests when that happens. Is there some way we could infer that from any of the tools available from the array?