move and expand the Objects and Paths section

[pve-docs.git] / qm.adoc

diff --git a/qm.adoc b/qm.adoc
index 5d0225db806f122dbb2dfaa9c63c763791f47cd7..ec709d80eabe72fc904b14b70902f71ac86d8a91 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -29,7 +29,7 @@ endif::manvolnum[]
 // http://pve.proxmox.com/wiki/KVM
 // http://pve.proxmox.com/wiki/Qemu_Server
 
-Qemu (short form for Quick Emulator) is an opensource hypervisor that emulates a
+Qemu (short form for Quick Emulator) is an open source hypervisor that emulates a
 physical computer. From the perspective of the host system where Qemu is
 running, Qemu is a user program which has access to a number of local resources
 like partitions, files, network cards which are then passed to an
@@ -56,6 +56,7 @@ module.
 Qemu inside {pve} runs as a root process, since this is required to access block
 and PCI devices.
 
+
 Emulated devices and paravirtualized devices
 --------------------------------------------
 
@@ -86,12 +87,14 @@ up to three times the throughput of an emulated Intel E1000 network card, as
 measured with `iperf(1)`. footnote:[See this benchmark on the KVM wiki
 http://www.linux-kvm.org/page/Using_VirtIO_NIC]
 
+
 Virtual Machines settings
 -------------------------
 Generally speaking {pve} tries to choose sane defaults for virtual machines
 (VM). Make sure you understand the meaning of the settings you change, as it
 could incur a performance slowdown, or putting your data at risk.
 
+
 General Settings
 ~~~~~~~~~~~~~~~~
 General settings of a VM include
@@ -101,6 +104,7 @@ General settings of a VM include
 * *Name*: a free form text string you can use to describe the VM
 * *Resource Pool*: a logical group of VMs
 
+
 OS Settings
 ~~~~~~~~~~~
 When creating a VM, setting the proper Operating System(OS) allows {pve} to
@@ -108,6 +112,7 @@ optimize some low level parameters. For instance Windows OS expect the BIOS
 clock to use the local time, while Unix based OS expect the BIOS clock to have
 the UTC time.
 
+
 Hard Disk
 ~~~~~~~~~
 Qemu can emulate a number of storage controllers:
@@ -122,18 +127,19 @@ on this controller.
 design, allowing higher throughput and a greater number of devices to be
 connected. You can connect up to 6 devices on this controller.
 
-* the *SCSI* controller, designed in 1985, is commonly found on server
-grade hardware, and can connect up to 14 storage devices. {pve} emulates by
-default a LSI 53C895A controller.
-
-* The *Virtio* controller is a generic paravirtualized controller, and is the
-recommended setting if you aim for performance. To use this controller, the OS
-need to have special drivers which may be included in your installation ISO or
-not. Linux distributions have support for the Virtio controller since 2010, and
+* the *SCSI* controller, designed in 1985, is commonly found on server grade
+hardware, and can connect up to 14 storage devices. {pve} emulates by default a
+LSI 53C895A controller. +
+A SCSI controller of type _Virtio_ is the recommended setting if you aim for
+performance and is automatically selected for newly created Linux VMs since
+{pve} 4.3. Linux distributions have support for this controller since 2012, and
 FreeBSD since 2014. For Windows OSes, you need to provide an extra iso
-containing the Virtio drivers during the installation.
-// see: https://pve.proxmox.com/wiki/Paravirtualized_Block_Drivers_for_Windows#During_windows_installation.
-You can connect up to 16 devices on this controller.
+containing the drivers during the installation.
+// https://pve.proxmox.com/wiki/Paravirtualized_Block_Drivers_for_Windows#During_windows_installation.
+
+* The *Virtio* controller, also called virtio-blk to distinguish from
+the Virtio SCSI controller, is an older type of paravirtualized controller
+which has been superseded in features by the Virtio SCSI Controller.
 
 On each controller you attach a number of emulated hard disks, which are backed
 by a file or a block device residing in the configured storage. The choice of
@@ -400,7 +406,7 @@ with a press of the ESC button during boot), or you have to choose
 SPICE as the display type.
 
 
-Managing Virtual Machines with 'qm'
+Managing Virtual Machines with `qm`
 ------------------------------------
 
 qm is the tool to manage Qemu/Kvm virtual machines on {pve}. You can
@@ -436,7 +442,7 @@ All configuration files consists of lines in the form
  PARAMETER: value
 
 Configuration files are stored inside the Proxmox cluster file
-system, and can be accessed at '/etc/pve/qemu-server/<VMID>.conf'.
+system, and can be accessed at `/etc/pve/qemu-server/<VMID>.conf`.
 
 Options
 ~~~~~~~
@@ -447,7 +453,7 @@ include::qm.conf.5-opts.adoc[]
 Locks
 -----
 
-Online migrations and backups ('vzdump') set a lock to prevent incompatible
+Online migrations and backups (`vzdump`) set a lock to prevent incompatible
 concurrent actions on the affected VMs. Sometimes you need to remove such a
 lock manually (e.g., after a power failure).