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Archive for January, 2011
Welcome to the Dutch Hyper-V Community. We are trying to bring IT-Pro’s and Vendors together to provide everyone with the correct information. On a regular basis we organize meetings around Hyper-V, our goal is to do this on a quartely basis.
We’ve upgraded our site the last couple of weeks. New version of WordPress running on Windows Server 2008 R2 Web Edition (and the VM is running on Hyper-V of course) and we welcome two new authors:
- Maarten Wijsman – Senior Infrastructure Engineer at Wortell, shifting his focus to Hyper-V. You can find Maarten’s blog here: http://www.hyper-v.nu/blogs/maarten;
- Peter Noorderijk – Consultant at PQR, focussing on Exchange and Virtualization. You can find Peter’s blog here: http://www.hyper-v.nu/blogs/pnoorderijk;
If you have any comments, questions or feedback, do not hesitate to contact us at email@example.com
The team of Hyper-V.nu
Ever since the appearance of Hyper-V in the market, I have been stressing and promoting the blessings of the Microsoft Virtualization platform. I started writing articles and blogs about Hyper-V and joined Jaap Wesselius in the Dutch Hyper-V User Group which assembles quarterly in different parts of the country. We have been presenting Hyper-V and related technologies many times and have grown a small community in the Netherlands. My endeavors have even earned me an MVP, albeit not for Hyper-V but for Cluster. If you meet me on Twitter, you know that whatever I communicate on this social network deals with Hyper-V and System Center related topics. I use it to promote the further growth of Hyper-V.
We have seen Hyper-V version 1 still beta in Windows Server 2008, Hyper-V RTM as an update, the major update Hyper-V R2 and Hyper-V Server 2008 R2. Now we are looking forward to Hyper-V vNext, “the next version” of Hyper-V, Hyper-V in Windows 8, Hyper-V Next Generation, Hyper-V Cloud, Hyper-V 2012 or whatever the marketing people at Microsoft think will capture our minds. I personally believe not even the word Hyper-V is sacred and could be replaced if it serves a purpose.
In a TechNet blog Michael Kleef announced that the number of VM’s per logical processor (LP) has been increased from 8:1 to 12:1, a 50% increase of VM density.
The increased ratio is supported if all guests run Windows 7. This is clearly aimed at Virtual Desktop Infrastructure (VDI) environments on Hyper-V R2. During the keynote of TechNet Europe 2010 we already heard increased VM density per host by at least 40%.
It is not uncommon that hardware vendors have to fix their array controller firmware. In this case it is HP’s P2000 G3 firmware for the FC/iSCSI combined models. Again it is a fix for problems as a result of customers using bigger clusters. Here we have a problem with Windows Server 2008 R2 clusters which surfaces with bigger clusters, long IQN names and a maximum of the space available for SCSI-3 reservations. Haven’t we seen this kind of trouble before. I can assure you that admins of Hyper-V R2 clusters surpassing these limits weren’t all that happy.
Using a long IQN name for iSCSI initiators may lead to issues while using SCSI-3 reservations and Persistent Group Reservations, particularly when trying to create large clusters with multiple paths to each LUN. A predefined area is used to store SCSI-3 reservation keys for each initiator path to each LUN and, when a large number of IQN entries are attempted to be stored, the array can run out of space in this area. This issue is dependent on the number of nodes and the number of paths per node accessing individual LUNs. This issue has been seen during the cluster validation process on Windows 2008 R2 clusters with 16 nodes, where each node had 4 paths to each LUN of the array.
In his blog Juan Manuel, a senior technical engineer working for HP, has completed his four-part sequel explaining the setup for HP Virtual Connect in HP BladeSystem.
It is a very good summary of how the different parts of a Virtual Connect domain can be configured:
HP Virtual Connect Domain Setup – Part 1: Domain Setup Wizard
HP Virtual Connect Domain Setup – Part 2: Network Setup
HP Virtual Connect Domain Setup – Part 3: Storage setup
HP Virtual Connect Domain Setup – Part 4: Server Profiles
Here are also a few links to some of my blogs regarding HP Virtual Connect:
I you are not the typical RTFM installer, you probably install your Hyper-V server by throwing in a HP SmartStart DVD and do the guided install that prepares your System Configuration, OS installation and HP ProLiant Support Pack. Well if you are that kind of person: be careful!
If not treated well, you would end up with problems stemming from a wrong installation order. If you want HP ProLiant NIC Teaming to work properly, you always have to enable Hyper-V with latest updates and hotfixes before you install the HP ProLiant Teaming Software. If you don’t, the network team may stop passing traffic.
I read a tweet from Virtualization MVP Kurt Roggen. In his blog Kurt mentioned that HP had published an update on the proper use of HP NIC Teaming.
The HOWTO document explains what happens if you create or dissolve a team if a Hyper-V virtual network was already configured and more importantly how to get rid of this.
The other topic discussed is the use of VLANs with Hyper-V. Last year I wrote a couple of blogs on native Hyper-V VLANs and the new promiscuous mode introduced in the NCU 10.10.xx version. I suggest you use the newer 10.20.x.x versions for reasons I mentioned in one of my previous blog.
The 4th edition of the HP document dated December 2010 can be found here.
Related blogs about HP NIC Teaming:
In October 2010 HP published a customer advisory, warning for cluster resource failures in large Microsoft Windows 2008 and R2 clusters using multiple host NICs with HP P4000 SAN and its Device Specific Module (DSM) for MPIO.
If any combination of cluster nodes, MPIO NIC ports and storage nodes resulted in more than 31 iSCSI sessions per volume, these issues would surface. Cluster Validation tests would in fact fail in these configurations. Adding a cluster node or storage node without validation would fail or only partly work.
HP published a firmware update with patch 10085-00 increasing the number of iSCSI sessions from 31 to 64. HP promised to solve this problem in its next major release of P4000 SAN/iQ software.
The formula for calculating the number of iSCSI sessions is:
# of Microsoft cluster nodes *
( # of initiator NICs per cluster node * # of storage nodes)
Now that SAN/iQ 9.0 has been released we can see that HP has followed up on this issue:
A HP Support document released in December 2010 states that with the new release, it has solved problems with SCSI Persistent Group Reservation (PGR) by increasing the limit to 256 iSCSI sessions per volume. This number is high enough to cope with 16 cluster nodes and 8 storage nodes with two iSCSI network adapters. This adds up to 16 x 2 x 8 = 256: so still be careful with bigger configurations.