Showing posts with label AUS. Show all posts
Showing posts with label AUS. Show all posts

Tuesday, July 18, 2017

Best practices while building a Hyper-V host

This article explains briefly about some of the best practice considerations while building a stand-alone Hyper-V 2012 R2/ 2016 host. You can use any compatible hardware, but here I will be explaining using Dell PowerEdge servers as I am working with them everyday.

  1. Select proper hardware

    You have to be really careful before purchasing a server. Analyze the requirements first and work a bit on capacity planning too. For example, PowerEdge R630 will be a good choice to start with as it is a 1U system with 2 processors. It can have up to 1.5 TB memory, but generally most SMB customers go with somewhere around 128 GB. Choosing the right network controller is also very important as it directly impacts the data transfer performance of the virtual machines. If you are planning to use converged networking on the host, select appropriate adapter. I recommend using one 10G dual port network card at the minimum for a converged network configuration. If you are looking for redundancy at network card level, then you can go with two 10G dual port cards. You can also go forward with multiple dual port or quad port 1G cards as per your requirements in case of budget limitations.  

  2. Number of disks, type of disks and RAID controller

    On a stand alone host, mostly customers will be using the local drives and if they need additional storage it will be provisioned from a SAN. The number of disks and the type of disks (SSD, SAS, NL-SAS etc.) will have direct impact on performance at storage level. Also, it is very important to select the right RAID controller. RAID types supported, size of controller cache, read/ write policies etc. are some of the major parameters that you have to consider while choosing the RAID controller card. Dell uses PERC (PowerEdge RAID Controller). For example, you can select PERC H730P which has 2 GB cache memory and a BBU and supports RAID levels 0,1,5,6,10,50 and 60. H710P also supports 4 KB block size disk drives. For more info please have a look at my article RAID configuration using PERC.

  3. Always use and follow HCL (Hardware Compatibility List)
  4. Configure out-of-band management. Dell uses iDRAC which helps you to manage your server remotely
  5. Update BIOS, firmware and drivers to the latest and greatest version
  6. Make sure you install all the necessary Windows updates
  7. Partition style, file system and AUS (Allocation Unit Size) of the drive where VM files will be saved

    Say, you are going to save all the VM files in drive D. While creating this drive select GPT partition style. If you are running Hyper-V 2012 R2, then use NTFS file system with AUS 64 KB. If you are having Hyper-V 2016, then use ReFS with 4 KB AUS. Please refer this MSFT article for more info.

  8. Always create a NIC team and select right teaming modes

    The most widely used teaming mode is switch independent + dynamic load balancing as it is the least complicated in terms of configuration and has no dependency on your switches. But if your switches support VLT (for Dell) or vPC (for Cisco) technology then the best teaming mode will be LACP + dynamic load balancing which provides you redundancy as well as aggregated throughput of all the active links in the team.

  9. Use separate VLANs for different types of traffic

    It is recommended to use separate VLANs for management, VM traffic, iSCSI, live migration and iDRAC.

  10. If using converged networking assign proper minimum bandwidths. Reference article for QoS recommendations linked here.
  11. Use minimum number of vSwithes
  12. Configure MPIO if adding additional storage from a SAN
  13. Set jumbo frames for iSCSI interfaces 
  14. Disable NetBIOS over TCP/ IP and DNS registration on iSCSI NICs

    Please check my post: Best practice recommendations for iSCSI network adapters

  15. Enable shared nothing live migration. For more info please check my previous post 
  16. If using 10G NICs make use of VMQ

    Please have a look at this MSFT article which provides you tips on VMQ CPU assignment

  17. Add exclusions for VHD/ VHDX files from scanning if antivirus is installed
  18. Run necessary stress tests to benchmark the system

    Benchmarking helps to get an overview of the IOPS numbers in the best/ worst case scenarios, so that you can provision your workload accordingly avoiding IO congestion at storage level. You can use synthetic benchmarking tools like iometer, diskspd etc. for conducting stress tests. Also go through my article:  How to calculate total IOPS supported by a disk array. But please note that these calculations doesn't take in to account on the effect of controller cache. That means the actual IOPS values while benchmarking the system will be higher than that of the values you got from the formula which is because of the effect of cache. When you select a write-back policy, all write IOs will land directly on the controller cache and will be acknowledged. Later those will be flushed to the disk array. Larger the cache size higher the IO performance. This shows the importance of choosing the right RAID controller.

  19. Choose OS power plan High Performance
  20. Make sure PSRemoting is enabled
  21. Enable proper monitoring either using a monitoring tool or custom scripts
  22. As a DR plan you can consider using Hyper-V replica
  23. Enable RDP
  24. I strongly recommend to create a diagram to visualize connectivity of the host to your network
  25. Organize VM files and folders properly as shown below
Here all VMs are stored in E:\VM folder

Virtual hard disks, VM config files, Snapshot files etc. of each VM is organized in a proper folder structure

I hope this will be helpful if you are totally new to Hyper-V and please feel free to let me know if you have any other best practice suggestions which I missed to mention here. Cheers!