Hello,
I have Windows Server 2012 R2 with Hyper-V activated.
I want my Linux VMs to have direct access to the NICs, without interference of Hyper-V (probably no Virtual Switches). Is it possible?
I read about SR-IOV and Enhanced Session Mode Policy which seem to be what I want, but the former is not always available (what can be a problem) and the later is only for Windows 8 and Windows 2012 VMs.
Could you please advise me on this?
Thanks in advance.
Hello All,
I have server 2012 R2 host server installed with Hyper-V role. I have configured a guest VM with server 2008 R2.There are 2 NICs on host.
Both are Broadcom NetXtreme Gigabit Ethernet adapters. I have also enabled NIC teaming between them.
On host I can see 4 adapters under Network Connections:
1. NIC1
2. NIC2
3. Team NIC
4. vEthernet (Microsoft Network Adapter Multiplexor Driver)
in Hyper-v, External switch is created using the Microsoft Network Adapter Multiplexor Driver (There is no other adapter available to select).
I am facing the issue with guest vM. Every 15-20 days, the network adapter from the vm vanishes. I cant access internet from Gust VM. I can ping to Gateway, host server. But no internet.
Please help me to resolve this issue permanently. Every time I have to setup new VM.
Regards,
Kuldeep.
I have a 2008r2 Server VM dedicated to running Microsoft SQL server 2008r2 with 4 VHD's (each corresponding to a drive on the server). VM's are hosted on a SAN using a cluster shared volume. I have 2 hosts in cluster.
VHD and corresponding guest OS drive
1 - c: system disk which is a dynamic disk
2 - e: Applications on fixed size disk
3 - f: logs and backup on fixed size disk
4 - g: databases on fixed size disk
This was set up about 2/3 years ago and was running well. Recently the server crashed and when I investigated I saw that the c:drive VHD had expanded in size so that that it filled all the space on the CSV. I initially increased the size of the CSV to get the server running again.
I noticed that the VHD containing the c: drive is growing about 50GB a day while the guest c:drive on the VHD is only getting marginally bigger. I have compacted the VHD and this brought the size of it down to the same size as the guest c:drive. Unfortunately since the compact it continues to grow at a rate of approximately 50GB a day.
I have done some research but cannot see an identical issue. This behaviour must have only started to occur recently otherwise this issue would have become apparent sooner.
Has anyone any ideas why this is happening
I can schedule a weekly compact as a work around.
I have seen information where the dynamic disk will continue to grow but this will only happen as the guest dive grows.
If I convert the dynamic disk to a fixed disk will that resolve the issue?
Any advice / information would be appreciated.
Regards
Niall
Hi,
I am looking for some advice on what the best way to configure my disk system is for performance when using Hyper-V. Currently I have two midline 7.2k SATA disks used for the hyper-V OS in RAID 1, and then 14 x 10k 600GB SAS enterprise disks in RAID 10. The RAID 10 is where all my VM’s exist on, but not directly on the physical disk, I use a product called StarWind which consumes almost all of the physical disk space, this is a virtual SAN and I use this for my CSV in the cluster, the VM’s all exist on this starwind disk, there is a tiny amount of overhead but I don’t think that’s really where my problem lies. We have 12 Virtual machines, so there is 1 spindle per VM, however it’s in RAID 10 so does this actually mean I have 7 spindles for 12 VMs?
The entire system almost grinds to a halt whenever I am copying new VM’s onto this host. I can’t use any other RAID type except for RAID 1 or 10. I know RAID 0 would give me better performance but we are not willing to take the risk. Now, it is my understanding that RAID 1 and 10 are essentially the same with the same performance and capacity, because of this I chose RAID 10 so I can take advantage of the combined capacity, but I am wondering if this is the best configuration.
I can think of a few other variations:
Reading this site, there are a few pointers I have taken away regarding disk performance, a couple below I have questions about.
http://www.altaro.com/hyper-v/23-best-practices-improve-hyper-v-vm-performance/
Point 6 says “Use separate volumes for each VM. Since the administrative tasks of a virtual machine are controlled by its own process (VMWP.exe), keeping several virtual machines on a single volume will cause more Disk I/O operations from each worker process. Hence, it is recommended to use separate volumes for storing virtual machine files (VHD, VHDx, checkpoints, and XML).”
Does this mean the arrangement I propose in my second point above – multiple partitions and a CSV on each partition? The term “Volume” seems to be a bit ambiguous depending on where you read
I believe point 14 to be incorrect though. “De-fragment Hyper-V Server regularly or before creating a virtual hard disk. It is advisable to defrag Hyper-V Server disks where the VHD and virtual machine configuration files are stored regularly or before creating a large virtual hard disk file.”
It is my understanding that defrag only tends to work well if there are many files on the disk, on the physical disk in my case there is one massive starwind file so I don’t think defrag on the physical will do anything, defrag in the starwind disk might help but it is mostly large VHDX files – will defrag really make much difference?
Additionally, I don’t have any generation 2 VM’s and there’s nothing I can do about this right now, all data disks use SCSI channels on the VMs, all VHDX are fixed size.
Also, a slight side question but kind of related – I have both an exchange server and SQL server running as VM’s (the log files already exist on separate VHDs, but on the same physical RAID 10 disk), does my physical disks used for log files need to match those used for the DB, or can they be slower lower class disks… for example, if I place a 7.2K disk in with a RAID made up of 10K disks, it is my understanding that the entire RAID will lower its performance of the slowest member – is this true with log files and databases, if the log files are on slow disks will the database also go slower to match the pace of log files being written?
many thanks
Steve
My company is moving heavily into virtualization. We have about 50 HW servers and 2 HyperV 2008 single hosts. I just built a pretty beefy Hyper-V 2012 clustered server and connected it to a brand new SAN.
I've read several articles before building the system to ensure that i follow those best practices, like this one.
http://blogs.technet.com/b/askpfeplat/archive/2013/03/10/windows-server-2012-hyper-v-best-practices-in-easy-checklist-form.aspx
The new system is running great. It has a dedicated NIC for live migrations, which has been tested.
My questions are really about resource usage. Determining how many virtual machines to put on one physical NIC, and how many virtual processors to give a virtual machine. I found an article that described mathematically what my limits are for a single virtual server. My server has 24 cores with 48 logical processors and 512 GB RAM.
What i'm not sure of is how many virtual processors I should give a machine. What I'm doing currently is starting small and just visually rating performance. If the machine seems slow i turn it off and give it two more processors. Does this sound like a good method?
Also, does anyone know how processor affinity work for HyperV. I would assume that HyperV balances threads across all cores. Or does it load up cores first them move to others.
Then there are the physical NICS. The back end ISCSI nics for the SAn are 10G and isolated and HyperV isn't allowed to use them. The front end NICS for the virtual servers are 1G. I'm watching them for load, but they seem to be no where near saturated. How many virts should I put on a single NIC? Is it just based on saturation or are there other considerations?
Thanks,
Several months ago we got a call from a client with a standalone 2012 R2 HyperV host: Absolutely NO network traffic was going through any of the virtual switches, yet we could see no errors or warnings of any kind in any of the logs. Desperate to get them back up and running we simply deleted all the virtual switches, recreated them (identical to what they were) and reattached all the VMs. We chalked it up as a fluke....until today:the EXACT same thing happened to a completely different customer.
Clearly there is something systemic here which needs to be addressed. I dont want to get another call in the middle of the night to have to recreate virtual switches.
Hi,
I got an error message randomly when I connect Hyper-V Server 2012 via Hyper-V Manager in MMC. The message said: Cannot connect to the virtual machine. please retry. But I can see all status on my virtual machines include screenshot.
The Hyper-V Server and the manage PC are in the same domain.
Can you help me? Thanks.
Lin Xiang Correct Solutions
I am trying to download the Eval for Hyper-V Server 2012 R2.
I keep getting the same error message:
Unable to save File
Please try again to save to a different location.
I have tried this on multiple computers and browsers, all with the same error.
what am I doing wrong?
I have hundreds of Citrix and Vmware servers. Decided to give Microsoft a try and was going to Migrate to them. Got a Server and installed Hyper-V On it. I did NOT join it to a domain. I completely patched it and all went well. Got a second server and installed Server 2012 R2 Standard. Fully patched it. Went into Hyper-V Manager and tried to connect to the Server and got a MMC error. It gives two options. Report to Microsoft and close or ignore error. When I ignore it gives me the following error, "FX:(922180d7-b74e-45f6-8c74-4b560cc100a5) Type"Microsoft.Virtualization.Client.Common.VirtualizationException' in assembly etc...and says SecurityKeyToken is not marked as serializable. Then at bottom it says Exception Type: System.Runtime.Serialization.SerializationException and has three Exception stack trace:....If I hit ok it closes.
I also formatted the server and installed Server 2012 R2 Standard and did NOT do any patches and I get the same thing. Neither server is joined to a domain. Both are workgroup with static IP's.
Hello All,
I have created Hyper-v machine in windows server 2012 environment. And install exchange server in that hyper-v machine. Hyper-v machine hdd configured by dynamic disk. now the size is increase and I delete the file from hyper-v machine. now I need to reduce the hyper-v machine size. please what is the procedure to reduce hyper-v vhd file size.
please suggest. thanks
Dears,
I have a little information about below, and I kindly wants your help.
I am using Windows 2012 R2 cluster with Hyper-V replica broker from my main site to DR site.
I have 2 VMs in main site failed today (1 is running SQL, and another one is running IIS),
Thank you
Hi,
I'm trying to enable replication on a VM that is part of a windows 2012 hyper-v cluster to a standalone hyperv 2012 server. Everytime i run the replication wizard i get to the end of the process and get the following error:
I'm using Kerbaros authentication and not Cert based using port 80.
Hyer-V failed to enable Replication.
Hyper-V failed to enable replication for virtual machine 'VM Name' The cluster resource is not available. (0x8007138E).
all the servers are part of the same domain and are on the same network.
Many thanks for your help.
Nick
Hi - We're in the process of implementing a multi-instance SQL 2014 guest cluster on Windows 2012 R2. To our dismay, it seems that Windows System Resource Manager (WSRM) is deprecated in Windows 2012 R2, so we're now stuck for how best to manage CPU
usage between SQL instances....
As far as I can see, I'm left with two options, but both of these have problems:
1) Use SQL Processor affinity within the guest cluster, with each SQL instance assigned to dedicated v-CPU. However, I'm not certain that setting SQL Processor affinity within a VM will actually have the desired affect!?..
- When there is physical CPU capacity available, I'd hope Hyper-V would provide it to whichever v-CPU is demanding it.
- When VM processor demand exceeds the physical CPU capacity, I'd hope the SQL instances would receive a proportion of the physical CPU time according to the number of v-CPU(s) assigned through the affinity settings.
2) Use a VM (actually 2, because its a 2-node guest cluster) per SQL instance!.. This is not ideal, as we need multiple SQL instances and it would result in have an administrative and performance overhead
Does anyone have any information or thoughts on this? How can we manage a virtualised multi-instance SQL deployment now that WSRM has been deprecated? Help me please!
Hi, I have approx 800 virtual machines, on a FailoverCluster, connected using FC to a Compellent SAN (50% SAS, 50% SATA). some Windows 2003 R2, some Windows 2008, some Windows 2008 R2, some Windows 2012 and some Windows 2012 R2.
I tried VMs on both Windows Server 2012 and Windows Server 2012 R2.
When I copy a file over an IDE disk, I never go over 90 MB/s. 100 MB/s when copying from the network to the Drive.
When I copy a file over a SCSI disk, I copy between 350 MB/s and 450 MB/s.
If I start a copy over an IDE disk, and, at the same time, I start a copy over a SCSI disk, the copy speed on the IDE drop between 50 MB/s and 75 MB/s, and the SCSI disk copy at 350 MB/s+. Then speed come back on the IDE when the SCSI is over.
If I start two copy on two different IDE disks, the first copy will hang for a couple second when the second copy starts, and I won't go over 70 MB/s on each disk.
The 3 disks are Fixed, and on the same CSV (same LUN). When doing file copy on the HOST, I have the same performance as the SCSI VHDx.
When I create Gen 2 VMs (100% SCSI), they are incredibly more responsive than the Gen 1 (IDE).
How can I fix the IDE performance? Thanks!
Hugo Monge
I have a single Physical host running 2012R2, which in turn hosts 2 VM's both running 2012R2. All of local disk.
I have configured a backup of the VM's using a third party tool.
When the backup runs I receive two warnings:
Event ID:58 - The disk signature of disk 3 is equal to the signature of disk 1
Event ID: 157 - Disk 2 has been surprise removed
I believe it is to do with VSS snapshots being taken at the time of backup and the backup is completing successfully, although in Hyper-v Manager the server up-time is from when these events occurred.
I have done some investigation and rule out things such as the disk ID being the same between the host and the guest.
I also seen people saying these can be ignored.
Does anybody have any further information of these warnings when VM backups occur or whether these warnings can be ignored?
Thanks
mark
Mark | http://syscen.blogspot.com/
So, I've migrated a server running CentOS 5.10 over to Hyper-V 2012. I am getting Kernel Panic from all available kernels when attempting to boot the migrated server.
I realize that I should have run Mkinitrd on the server before migration. I am still able to do this on the production server as it is still in place and I am just testing the migrated/ virtualized server.
Even so, my question is:
Is it possible to run the Mkinitrd command on the server that is experiencing Kernel Panic post migration?
Thanks and Cheers,
