Operating Systems

Hyper-V Host Clustering via ISCSI

Ryan Femling — Wed, 10 Dec 2008 01:06:31 GMT

There's a lot of articles out there about Hyper-V host clustering. But there isn't much about the associated caveats. The main issue I ran into was with creating new physical disk resources. When you create a cluster and add nodes to it, you may end up adding a disk resource from a machine that does not own the cluster group. Yes, contrary to what it looks like in the GUI, there are still cluster groups, and much of the underlying clustering administration is unchanged from server 2003. If you're in a situation where you need to add physical disk resources and the GUI won't see them, here's what you do:

1. On one of the nodes that is a possible owner for the resource, open two consoles as an administrator.

2. Log on to the LUN via the ISCSI administrator

3. In storage management, bring the disk online, initialize the disk, and create a simple volume (note, you can initialize the disk via MBR or GPT, but the disk MUST be a basic disk).

4. In the first command prompt you have open, type diskpart. Type select disk <appropriate disk number here>. And then type detail disk. You should see something like this:
MSFT Virtual HD SCSI Disk Device
Disk ID: 2E3EA1FE
Type : iSCSI
Bus : 0
Target : 10
LUN ID : 0
Read-only : No
Boot Disk : No
Pagefile Disk : No
Hibernation File Disk : No
Crashdump Disk : No

5. In the second command prompt, type Cluster res "<resource name here>" /create /group:"Available Storage" /type:"Physical Disk" This will create the resource.

6. In the second command prompt, type Cluster res "<resource name here>" /priv DiskSignature="0x<DiskID from first command prompt>" The 0x before the disk ID listed is important, and you won't be able to bring the disk online if you leave it out.

7. In the second command prompt, type Cluster res "<resource name here>" /on This will bring your new disk resource online.

When doing this, make sure that the Available Storage resource group is owned by a machine with access to the LUN you're trying to bring online. It seems that Microsoft wants you to grant access to every node in your cluster, but if you're like me and are a bit nitpicky about which machines have access to which LUNs, you'll want to follow these steps.

More clustering fun....

Ryan Femling — Sat, 03 May 2008 00:07:52 GMT

As you may or may not know, I love clustering. I've been working with MSCS for a very long time, and I look at it as a way to make my daily life easier. An admin with a cluster can have downtime on hardware in the middle of the day, can do patches at any time knowing that if there's a problem, all you have to do is fail back to an unpatched node. That and it makes for some really cool toys.

Up to the present. I decided to check out MSCS (now known as failover clustering) on Windows Server 2008. I'm a big fan of building your own ISCSI devices, and I like Openfiler and FreeNAS. Both provide a large list of features, and the capability of Openfiler to run a two-node failover cluster of it's own (thus providing redundant storage for your cluster) to be a wonderful thing. So, you can imagine my dismay when I discovered that faliover clustering in Windows Server 2008 requires support for persistent reservations by your iSCSI target. Unfortunately, none of the free ISCSI target solutions support this yet. When they do, I'll be sure to update with more info.

Back to a blast from the past, clustering on windows server 2003. Here's another caveat for everyone out there: We'll often build our nodes with two disks in them and mirror those disks. Be careful about what method you use, some onboard RAID solutions will use BUS0 for their volumes. If this is the case with your RAID controller, switch to software mirroring. The reason is that the ISCSI initiator also latches on to BUS0, putting it on the same bus as your boot volume. This will cause cluster creation to pop up a warning about being unable to find a quorum device (BEWARE, no warning will pop up if you use the advanced creation option, you just won't be able to add any shared disks later).

Hyper-V and VLANs

Ryan Femling — Wed, 23 Apr 2008 18:06:49 GMT

I was excited when I heard that Hyper-V was going to include support for VLANs. What I didn't realize was that there would be some caveats to the deal. If you plan on using tagged VLANs to get support for multiple networks from one physical port, you need to know that Hyper-V works on a one-to-one relationship with interfaces.

To make it all work, you need to create your virtual interfaces (per the software and driver for your NIC) and assign them to the appropriate VLAN. Don't bother putting in any static IP information because as soon as you create a network in Hyper-V to accomodate your VMs, Hyper-V will create another connection on top of the VLAN adapter you've already created. Once this new interface is created, you can enter any static IP addresses there. Additionally, if you don't take into account the extra caveats below, you will have no network connectivity.

EXTRA CAVEATS:
1. Make sure you specify the correct VLAN number in the virtual network.

2. Make sure you specify the correct VLAN number in the network settings for the virtual machine.

XP Media and Thinkpads

Ryan Femling — Tue, 14 Aug 2007 23:43:00 GMT

I've seen it before and ran into it again today. On IBM T4x series laptops, OS installation fails from burned media (which you should only be using if you have a VL agreement with MS) if it was not burned on another T4x laptop. Now, bear in mind that this experience only involves 4 separate occasions, but I felt that was enough to warrant an eyebrow raising at the minimum.

IE and local XML files

Ryan Femling — Tue, 24 Jul 2007 17:12:00 GMT

I ran into an interesting issue today to which I found no ready solutions online. I finally figured it out and decided to post it here. If you experience an issue where you try to open a local XML file in IE, and IE just sits there blank displaying “connecting” as the status, try the reregistering msxml3 by clicking start>run and typing in “'regsvr32 msxml3.dll”.

Intel PRO/1000 NICs and tagged VLANs

Ryan Femling — Thu, 08 Mar 2007 00:16:00 GMT

Just a quick post about an interesting driver “feature” in the Intel PRO/1000 chipset. When you install the driver package in Windows, and select a full install, you'll find that you can't access the advanced management features via RDP. If you're planning on using this driver with a server, and, like me, you performed the install via an RDP connection, save yourself the frustration of trying to figure it out. The driver install works, but to specify VLANs for your NIC, you have to be present in front of the box unless you have a remote control software like SMS.

MSCS Caveats

Ryan Femling — Wed, 07 Feb 2007 22:21:00 GMT

I simple online search will provide you with thousands of opinions on this topic. What I've found in my travels, is that it all comes down to the situation.

Windows Server 2003 VMs and sound

Ryan Femling — Mon, 18 Dec 2006 21:37:00 GMT

As you may have noticed, native sound in a virtual machine in Virtual PC containing a Windows Server 2003 install does not work. The way around this is to pull two files from an XP install disk. From the i386 folder, use the expand.exe (also located in that folder) to extract the wdma_ctl.in_ file to an alternate location. Once you've done that, rename the extension to .inf. After that, you'll need to pull the ctlsb16.sys file from the driver.cab file. Once the files are extracted, do a manual driver update and point to the .inf file. The one key thing to remember is that you need to do this via a remote control session, NOT an RDP session, if not, you won't get prompted for the additional files needed from the server CD.

Some thoughts on Vista x64

Ryan Femling — Tue, 10 Oct 2006 18:14:00 GMT

Just a real quick post this time. I've read numerous reviews online both for and against Vista. I have recently migrated my desktop to x64 edition, build 5728 and decided I would try and cover the things I've noticed that I hadn't seen covered elsewhere.

Installation: Installing Vista x64 was the most problematic portion of the whole process for me. I am running a motherboard with an Nforce4 chipset on it, and during my first attempt at installation, it froze partway through the file copy process. After that, I tried disabling the USB controller (I had seen USB issues on a previous build). That took me almost completely through the install, but left me with a “Memory Management” blue screen of death. Still figuring it to be a driver issue, I went to NVidia's website and downloaded all of their drivers for Vista RC1, and tried each one at the disk partitioning portion of setup with the “Load Driver” option. Finally my install completed.

Post install: After I got booted into Vista for the first time after setup, I rebooted and re-enabled the USB controller. My computer booted up, and I seemed to have no problems. A short time after this, however, I plugged in an external USB HDD, and recieved the same “Memory Management” BSOD from before. I searched all over, seeing as this looked to be an obvious driver issue. After trying three versions of the x64 driver, the behavior didn't change, so I don't use USB drives.

Everything else that I would say has been said many times over online, so my conclusion is that if you can get it to install, Vista x64 has a lot going for it. Compared to XP x64, it's miles ahead in usability, application compatibility, and speed. When I compare the OS tweaks I made to Vista, to those I made in XP (see previous post), on the same hardware, Vista is just faster with fewer changes needing to be made (the changes I made in Vista were for preferences, not performance).

The two+ year OS install

Ryan Femling — Tue, 08 Aug 2006 16:55:00 GMT

I felt it would be a good idea to revisit the basics of what makes a stable, high performance XP install. To this end, I've decided to post my methods as if I were installing a new system:

1. Your hardware. Starting at the bottom of the OSI model, the first thing that needs attention is the hardware upon which your install will take place. If you're using old hardware that's seen service, review the event logs before wiping the drive and look for any errors that may be indicative of drive or other hardware failure. Remember, those intermittent CD-ROM drive errors may cause read issues during install, causing the whole process to fail (this is from experience). Another thing to remember, is that if you have no other drivers handy on CD or USB drive, have your network drivers handy. Just in case. If you're using new hardware, make sure you have the drivers for any disk controllers that your drives are plugged into.

2. RAID There are a lot of motherboards these days that ship with onboard RAID capabilities. In many cases, the performance of these devices is subpar. If you don't have a dedicated RAID card, and need mirroring, your best bet is to use the built-in functionality of windows. To be sure about the performance, research your particular chipset online.

3. Partitioning I still make at least two partitions when doing an OS install. The reason for this is that if you move your paging file and temp files to a second partition, it cuts down on fragmentation. If your second partition is on a separate physical drive, you can see a significant performance increase as well.

4. Page File My personal metrics have seen the best performance on average when I set the page file to be twice the amount of physical ram. Make sure that you set the initial and maximum size of the file to be the same. It's a small gain, but keeping the OS from having to resize the page file saves resources (and helps cut down on fragmentation).

5. Prefetch The c:\windows\prefetch folder is supposed to improve application and OS startup time by reading expected data into the cache. In practice, I have found this folder to be the number one cause of slow startup times . I advise that the contents of this folder be deleted, and the permissions on it modified to deny access to the local system account. On my machine, doing the preceding steps reduced startup time by eighteen seconds. (A note for Vista enthusiasts: My testing so far of Vista beta2 has shown that the "superfetch" feature works very well, and lives up to the promises of what prefetch was supposed to do for XP)

6. Services Following is a list of services that can be disabled to help with performance, stability, and security:

Alerter - Most environments don't use this method of notification any more.
ClipBook - Most users don't need to share the contents of their clipbook viewer directly to other machines
Computer Browser - In a network environment, it's usually best to enable this on a few servers, but not a workstation
Distributed Transaction Coordinator - Not needed on most workstations
Error Reporting Service - Not needed, this is what prompts you to send error messages to MS.
Fast User Switching Compatibility - I have seen people have difficulty with this when two large profiles are loaded simultaneously
Help and Support - I use http://www.microsoft.com/technet if I run into a situation where I need help, it's much more useful than the help service.
Machine Debug Manager - If you have office, you have this service. I have seen it cause system hangs while it tries to sort out an issue.
Messenger - SP2 disables this service, but I always double check anyway.
Network DDE - If you disabled the ClipBook service, chances are that you won't need this.
Network DDE DSDM - See Network DDE
Network Location Awareness - Some people will tell you this is necessary for the windows firewall to work. On my machines, it is disabled and the firewall works fine, and still stands up to my pen-tests.
Portable Media Serial Number Service - The need for this service depends upon your mp3 player. Most will work fine with it disabled.
SSDP Discovery Service - Some people like this service for UPnP functionality. I disable this service to have one less service running, and due to my lack of faith in the security of UPnP.
WebClient - The functionality of this service can be replicated with IE
Wireless Zero Configuration - If you don't have a wireless card, or don't want XP to manage your wireless card, disable this service.

7. Updates Once you've installed and configured your system, the next step should always be to get updates from MS. When updating, I always leave off the malicious software removal tool, and am very selective about non-critical updates I install. Don't install the .net framework 1.1 if you don't need it.

8. AntiVirus Anyone whos read the news much in the past year or two can see that AV software is a must have. My personal favorite is Symantec AntiVirus (not Norton). This is a lightweight, non intrusive AV that, most importantly, has never failed me.

9. SpyWare If you browse the internet, you'll run into spyware. On my personal machines, I run Ad-Aware and SpyBot once a week to keep things looking good. The other necessary app for keeping your machine running well is hijackthis. HiJackThis will give you visibility into exactly what is running on your system during startup and gives you an easy way to change it. This is helpful for all of those media apps that most people want on their machines that set themselves to start with the OS.

10. Ongoing maintenance Things to do from time to time:

Defrag your drives
BACKUP YOUR DATA
Run ChkDsk
BACKUP YOUR DATA
Review your error logs for evidence of possible issues
BACKUP YOUR DATA

Following these procedures and being smart about my web browsing has enabled my oldest machine to have run for over two years with no performance degradation.