A very simple way to see what command line options client Windows Update Agent (wuauclt.exe) has is to drop the executable in notepad. In the beginning of the notepad (Word wrap enabled) you will find them!
In Windows 7 these options are available:
/DetectNow
/ReportNow
/RunHandlerComServer
/RunStoreAsComServer
/ShowSettingsDialog
/ResetAuthorization
/ResetEulas
/ShowWU
/ShowWindowsUpdate
/CloseWindowsUpdate
/SelfUpdateManaged
/SelfUpdateUnmanaged
/UpdateNow
/ShowWUAutoScan
/ShowFeaturedUpdates
/ShowOptions
/ShowFeaturedOptInDialog
/DemoUI
Many of them are undocumented. What some of them mean can be found on the interwebs, others I have no clue!
So, what does this picture mean?
By default, volumes are spread across three members in one pool. So if you have six arrays in a pool, a different combination of three members will be used to handle different volumes.
There is a maximum of 16 nodes in a Hyper-V cluster which means every node in the cluster will get 6 persistent rervervations on a volume (96/16 = 6).
These 6 persistent reservations per node are then spread over a maximum of 3 members in a pool. We will then get 2 connections per member. If we apply redundancy this will result in 1 connection per NIC per Hyper-V cluster node.
If the above is correct then my previous post (http://www.delltechcenter.com/thread/4007957/Microsoft+Windows+2008+R2+CSV+and+Equallogic+SAN/ or http://www.martius.nl/?p=1896) on how to calculate the persistent reservations in wrong. This is because of the spread over max 3 members which actually means no mather how many Equallogics you are using(max. 16 in a pool) only 3 will be used to locate the volume.
The new calculation would then be:
Number of Equallogics = 3 (max spread)
Number of NICs = N
Number of MPIO = M (default HIT = 2)
Number of Servers = S
3 * N * M * S = 96
The numbers will then be:
3 * 2 * 1 * 16 = 96
Obvious question then is why should you use the DSM of Equallogic above the use of the standard Microsoft Multipath capabilities? The Equallogic DSM has a default MPIO per NIC of 2 while only one is available.
Another question is if this is the way Equallogic supports a 16 node Hyper-V cluster?
What are your thoughts? Please share them in getting this Equallogic – Persistent Reservation mystery clarified.
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