Need For Speed or easy tuning of virtual machines
Quite often, at seminars or when auditing a customer’s existing virtual environment, I heard reproaches: “Virtualization slows down”, “We tried to transfer the server to a virtual environment, and it got up”, “Virtual servers run slower than physical servers”. At the same time, nine out of ten such problems with the “inhibition” of virtual servers were solved by simple optimization of devices in the virtual machine.
A large number of questions on how to improve the performance of the virtual environment prompted me to write a short FAQ on optimizing VMware vSphere-based virtual machines - a platform used by most of our corporate clients. At the same time, I would like to note that for solutions based on Hyper-V and Xen Server the correct choice of devices is also able to speed up the work of virtual servers.
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Q: What are the types of virtual machine devices?
A: Types of embedded devices affect the algorithm of the virtual machine with the "iron", thus exerting a direct impact on performance.
Q: Why did VMware need to build unique virtual devices into the architecture instead of emulating ordinary controllers?
A: Virtual devices that have no real analogs are designed with the sole purpose of reducing virtualization overhead. Only with them it is possible to ensure that the speed of the virtual machine does not practically differ from the physical original.
Q: What is the difference between disk controllers?
A: Disk controllers affect the algorithm for processing SCSI commands. VMware Paravirtual is optimized for batch processing of commands, thus, with a large number of I / O operations, it is much more efficient than LSI Logic controllers.
Q: If VMware Paravirtual is so good, why is it not used by default?
A: Since VMware Paravirtual has no real analogs, it is not directly supported by operating systems. Consequently, the remaining controllers are needed solely for compatibility with older versions of guest operating systems. In addition, with a small number of I / O operations, it may be less efficient than LSI Logic SAS, which allows it to be recommended for use as a system disk controller.
Q: What operating systems support VMware Paravirtual?
A: The list of operating systems supporting VMware Paravirtual is shown in the table below.
Q: What disk controllers are better to use if VMware Paravirtual is not supported?
A: The preferred controller is LSI Logic SAS. Unfortunately, due to the huge variety of supported operating systems, it is not possible to bring them all under this review. Even if LSI Logic SAS is not supported, then you have to use LSI Logic Parallel.
Q: Where can I get drivers for VMware Paravirtual?
A: When installing the OS, you can install drivers from a virtual floppy disk drive. To select the image you need to specify in the properties of the drive "Use existing floppy image in datastore". Then you should specify the desired image from located in the / vmimages / floppies directory. Also, drivers for non-system disks can be added after installing the OS - for this you just need to install VMware Tools.
Q: Why can't thin disks be used in an industrial environment?
A: With each expansion operation of a thin disk, the speed of the VMFS volume on which it is located is significantly reduced, and expansion operations cannot be accurately predicted.
Q: Which network controller is most effective?
A: The most efficient type of network controller is VMXNET 3. By analogy with VMware Paravirtual, it allows you to reduce overhead costs and improve the performance of the network I / O subsystem.
Q: Why do we need network controllers other than VMXNET3?
A: The remaining network controllers are needed solely for compatibility with operating systems that do not support VMXNET3.
Q: What operating systems support VMXNET3?
A: VMXNET3 is compatible with the following types of guest OS:
Q: Where can I get drivers for VMXNET3?
A: VMXNET3 drivers are installed along with VMware Tools.
Q: Which network controllers are best to use if VMXNET3 is not supported?
A: Recommended after VMXNET3 is E1000. VMXNET2 is needed for compatibility with older versions of ESX / ESXi, and not with older versions of the guest OS. If even the E1000 does not fit, then you should use other network controllers that are compatible with the specific OS.
Q: What if the mouse cursor in a virtual environment moves jerky?
A: In Windows 7 and Windows 2008 (and above), you must manually install the video adapter driver. After installing VMware Tools, the video adapter driver is available in the C: \ Program Files \ Common Files \ VMware \ drivers \ wddm_video directory.
Alexey Khakimov, Senior Systems Engineer, Digital Design
A large number of questions on how to improve the performance of the virtual environment prompted me to write a short FAQ on optimizing VMware vSphere-based virtual machines - a platform used by most of our corporate clients. At the same time, I would like to note that for solutions based on Hyper-V and Xen Server the correct choice of devices is also able to speed up the work of virtual servers.
')
FAQ on working with virtual devices in a VMware vSphere environment
Q: What are the types of virtual machine devices?
A: Types of embedded devices affect the algorithm of the virtual machine with the "iron", thus exerting a direct impact on performance.
Q: Why did VMware need to build unique virtual devices into the architecture instead of emulating ordinary controllers?
A: Virtual devices that have no real analogs are designed with the sole purpose of reducing virtualization overhead. Only with them it is possible to ensure that the speed of the virtual machine does not practically differ from the physical original.
Q: What is the difference between disk controllers?
A: Disk controllers affect the algorithm for processing SCSI commands. VMware Paravirtual is optimized for batch processing of commands, thus, with a large number of I / O operations, it is much more efficient than LSI Logic controllers.
Q: If VMware Paravirtual is so good, why is it not used by default?
A: Since VMware Paravirtual has no real analogs, it is not directly supported by operating systems. Consequently, the remaining controllers are needed solely for compatibility with older versions of guest operating systems. In addition, with a small number of I / O operations, it may be less efficient than LSI Logic SAS, which allows it to be recommended for use as a system disk controller.
Q: What operating systems support VMware Paravirtual?
A: The list of operating systems supporting VMware Paravirtual is shown in the table below.
| Guest operating system | VMware Paravirtual supported as data disc | VMware Paravirtual supported as a boot disk |
| Windows Server 2008 R2 (64-bit only) | ESX / ESXi 4.0 Update 1, ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.0 Update 1, ESX / ESXi 4.1, ESXi 5.0 |
| Windows Server 2008 (32 and 64 bit) | ESX / ESXi 4.X, ESXi 5.0 | ESX / ESXi 4.0 Update 1, ESX / ESXi 4.1, ESXi 5.0 |
| Windows Server 2003 (32 and 64 bit) | ESX / ESXi 4.x, ESXi 5.0 | ESX / ESXi 4.x, ESXi 5.0 |
| Windows 7 (32 and 64 bit) | ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.1, ESXi 5.0 |
| Windows Vista (32 and 64 bit) | ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.1, ESXi 5.0 |
| Windows XP (32 and 64 bit) | ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.1, ESXi 5.0 |
| Red Hat Enterprise Linux (RHEL) 5 (32 and 64 bit) and higher | ESX / ESXi 4.X, ESXi 5.0 | Not supported. |
| RHEL 6 (32 and 64 bit) | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 |
| SUSE Linux Enterprise 11 SP1 (32 and 64 bit) and higher | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 |
| Ubuntu 10.04 (32 and 64 bit) and higher | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.0 Update 2, ESX / ESXi 4.1, ESXi 5.0 |
| Distros Linux 2.6.33 and up | ESX / ESXi 4.1, ESXi 5.0 | ESX / ESXi 4.1, ESXi 5.0 |
Q: What disk controllers are better to use if VMware Paravirtual is not supported?
A: The preferred controller is LSI Logic SAS. Unfortunately, due to the huge variety of supported operating systems, it is not possible to bring them all under this review. Even if LSI Logic SAS is not supported, then you have to use LSI Logic Parallel.
Q: Where can I get drivers for VMware Paravirtual?
A: When installing the OS, you can install drivers from a virtual floppy disk drive. To select the image you need to specify in the properties of the drive "Use existing floppy image in datastore". Then you should specify the desired image from located in the / vmimages / floppies directory. Also, drivers for non-system disks can be added after installing the OS - for this you just need to install VMware Tools.
Q: Why can't thin disks be used in an industrial environment?
A: With each expansion operation of a thin disk, the speed of the VMFS volume on which it is located is significantly reduced, and expansion operations cannot be accurately predicted.
Q: Which network controller is most effective?
A: The most efficient type of network controller is VMXNET 3. By analogy with VMware Paravirtual, it allows you to reduce overhead costs and improve the performance of the network I / O subsystem.
Q: Why do we need network controllers other than VMXNET3?
A: The remaining network controllers are needed solely for compatibility with operating systems that do not support VMXNET3.
Q: What operating systems support VMXNET3?
A: VMXNET3 is compatible with the following types of guest OS:
- 32-bit and 64-bit versions of Microsoft Windows XP, 7, 2003, 2003 R2, 2008, and 2008 R2 and higher;
- 32-bit and 64-bit versions of Red Hat Enterprise Linux 5.0 and higher;
- 32-bit and 64-bit versions of SUSE Linux Enterprise Server 10 and higher;
- 32-bit and 64-bit versions of Asianux 3 and higher;
- 32- and 64-bit versions of Debian 4 and up;
- 32- and 64-bit versions of Ubuntu 7.04 and up;
- 32-bit and 64-bit versions of Sun Solaris 10 U4 and higher.
Q: Where can I get drivers for VMXNET3?
A: VMXNET3 drivers are installed along with VMware Tools.
Q: Which network controllers are best to use if VMXNET3 is not supported?
A: Recommended after VMXNET3 is E1000. VMXNET2 is needed for compatibility with older versions of ESX / ESXi, and not with older versions of the guest OS. If even the E1000 does not fit, then you should use other network controllers that are compatible with the specific OS.
Q: What if the mouse cursor in a virtual environment moves jerky?
A: In Windows 7 and Windows 2008 (and above), you must manually install the video adapter driver. After installing VMware Tools, the video adapter driver is available in the C: \ Program Files \ Common Files \ VMware \ drivers \ wddm_video directory.
Alexey Khakimov, Senior Systems Engineer, Digital Design
Source: https://habr.com/ru/post/148026/
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