rewrite and extend pct documentation

[pve-docs.git] / qm.adoc

diff --git a/qm.adoc b/qm.adoc
index 81fd39ec06e3d8c55a5f2716deb0b8ec10de9dbd..0b699e24b0b440eb6f31b5922883f2b79092994b 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -144,12 +144,15 @@ hardware layout of the VM's virtual motherboard. You can choose between the
 default https://en.wikipedia.org/wiki/Intel_440FX[Intel 440FX] or the
 https://ark.intel.com/content/www/us/en/ark/products/31918/intel-82q35-graphics-and-memory-controller.html[Q35]
 chipset, which also provides a virtual PCIe bus, and thus may be desired if
 default https://en.wikipedia.org/wiki/Intel_440FX[Intel 440FX] or the
 https://ark.intel.com/content/www/us/en/ark/products/31918/intel-82q35-graphics-and-memory-controller.html[Q35]
 chipset, which also provides a virtual PCIe bus, and thus may be desired if

-one want's to pass through PCIe hardware.
+one wants to pass through PCIe hardware.

 
 [[qm_hard_disk]]
 Hard Disk
 ~~~~~~~~~
 
 
 [[qm_hard_disk]]
 Hard Disk
 ~~~~~~~~~
 

+[[qm_hard_disk_bus]]
+Bus/Controller
+^^^^^^^^^^^^^^

 Qemu can emulate a number of storage controllers:
 
 * the *IDE* controller, has a design which goes back to the 1984 PC/AT disk
 Qemu can emulate a number of storage controllers:
 
 * the *IDE* controller, has a design which goes back to the 1984 PC/AT disk


@@ -182,6 +185,10 @@ is an older type of paravirtualized controller. It has been superseded by the
 VirtIO SCSI Controller, in terms of features.
 
 [thumbnail="screenshot/gui-create-vm-hard-disk.png"]
 VirtIO SCSI Controller, in terms of features.
 
 [thumbnail="screenshot/gui-create-vm-hard-disk.png"]

+
+[[qm_hard_disk_formats]]
+Image Format
+^^^^^^^^^^^^

 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
 a storage type will determine the format of the hard disk image. Storages which
 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
 a storage type will determine the format of the hard disk image. Storages which


@@ -200,6 +207,9 @@ either the *raw disk image format* or the *QEMU image format*.
  * the *VMware image format* only makes sense if you intend to import/export the
  disk image to other hypervisors.
 
  * the *VMware image format* only makes sense if you intend to import/export the
  disk image to other hypervisors.
 

+[[qm_hard_disk_cache]]
+Cache Mode
+^^^^^^^^^^

 Setting the *Cache* mode of the hard drive will impact how the host system will
 notify the guest systems of block write completions. The *No cache* default
 means that the guest system will be notified that a write is complete when each
 Setting the *Cache* mode of the hard drive will impact how the host system will
 notify the guest systems of block write completions. The *No cache* default
 means that the guest system will be notified that a write is complete when each


@@ -215,16 +225,19 @@ As of {pve} 5.0, replication requires the disk images to be on a storage of type
 `zfspool`, so adding a disk image to other storages when the VM has replication
 configured requires to skip replication for this disk image.
 
 `zfspool`, so adding a disk image to other storages when the VM has replication
 configured requires to skip replication for this disk image.
 

+[[qm_hard_disk_discard]]
+Trim/Discard
+^^^^^^^^^^^^

 If your storage supports _thin provisioning_ (see the storage chapter in the
 {pve} guide), you can activate the *Discard* option on a drive. With *Discard*
 set and a _TRIM_-enabled guest OS footnote:[TRIM, UNMAP, and discard
 https://en.wikipedia.org/wiki/Trim_%28computing%29], when the VM's filesystem
 marks blocks as unused after deleting files, the controller will relay this
 information to the storage, which will then shrink the disk image accordingly.
 If your storage supports _thin provisioning_ (see the storage chapter in the
 {pve} guide), you can activate the *Discard* option on a drive. With *Discard*
 set and a _TRIM_-enabled guest OS footnote:[TRIM, UNMAP, and discard
 https://en.wikipedia.org/wiki/Trim_%28computing%29], when the VM's filesystem
 marks blocks as unused after deleting files, the controller will relay this
 information to the storage, which will then shrink the disk image accordingly.

-For the guest to be able to issue _TRIM_ commands, you must either use a
-*VirtIO SCSI* (or *VirtIO SCSI Single*) controller or set the *SSD emulation*
-option on the drive. Note that *Discard* is not supported on *VirtIO Block*
-drives.
+For the guest to be able to issue _TRIM_ commands, you must enable the *Discard*
+option on the drive. Some guest operating systems may also require the
+*SSD Emulation* flag to be set. Note that *Discard* on *VirtIO Block* drives is
+only supported on guests using Linux Kernel 5.0 or higher.

 
 If you would like a drive to be presented to the guest as a solid-state drive
 rather than a rotational hard disk, you can set the *SSD emulation* option on
 
 If you would like a drive to be presented to the guest as a solid-state drive
 rather than a rotational hard disk, you can set the *SSD emulation* option on


@@ -232,14 +245,16 @@ that drive. There is no requirement that the underlying storage actually be
 backed by SSDs; this feature can be used with physical media of any type.
 Note that *SSD emulation* is not supported on *VirtIO Block* drives.
 
 backed by SSDs; this feature can be used with physical media of any type.
 Note that *SSD emulation* is not supported on *VirtIO Block* drives.
 

-.IO Thread
+
+[[qm_hard_disk_iothread]]
+IO Thread
+^^^^^^^^^

 The option *IO Thread* can only be used when using a disk with the
 *VirtIO* controller, or with the *SCSI* controller, when the emulated controller
  type is  *VirtIO SCSI single*.
 With this enabled, Qemu creates one I/O thread per storage controller,
 The option *IO Thread* can only be used when using a disk with the
 *VirtIO* controller, or with the *SCSI* controller, when the emulated controller
  type is  *VirtIO SCSI single*.
 With this enabled, Qemu creates one I/O thread per storage controller,

-instead of a single thread for all I/O, so it increases performance when
-multiple disks are used and each disk has its own storage controller.
-Note that backups do not currently work with *IO Thread* enabled.
+instead of a single thread for all I/O, so it can increase performance when
+multiple isks are used and each disk has its own storage controller.

 
 
 [[qm_cpu]]
 
 
 [[qm_cpu]]


@@ -268,8 +283,8 @@ is greater than the number of cores on the server (e.g., 4 VMs with each 4
 cores on a machine with only 8 cores). In that case the host system will
 balance the Qemu execution threads between your server cores, just like if you
 were running a standard multithreaded application. However, {pve} will prevent
 cores on a machine with only 8 cores). In that case the host system will
 balance the Qemu execution threads between your server cores, just like if you
 were running a standard multithreaded application. However, {pve} will prevent

-you from assigning more virtual CPU cores than physically available, as this will
-only bring the performance down due to the cost of context switches.
+you from starting VMs with more virtual CPU cores than physically available, as
+this will only bring the performance down due to the cost of context switches.

 
 [[qm_cpu_resource_limits]]
 Resource Limits
 
 [[qm_cpu_resource_limits]]
 Resource Limits


@@ -507,7 +522,7 @@ host.
 .Fixed Memory Allocation
 [thumbnail="screenshot/gui-create-vm-memory.png"]
 
 .Fixed Memory Allocation
 [thumbnail="screenshot/gui-create-vm-memory.png"]
 

-ghen setting memory and minimum memory to the same amount
+When setting memory and minimum memory to the same amount

 {pve} will simply allocate what you specify to your VM.
 
 Even when using a fixed memory size, the ballooning device gets added to the
 {pve} will simply allocate what you specify to your VM.
 
 Even when using a fixed memory size, the ballooning device gets added to the


@@ -636,7 +651,8 @@ necessary footnote:[https://www.kraxel.org/blog/2014/10/qemu-using-cirrus-consid
 qemu: using cirrus considered harmful], e.g., if using Windows XP or earlier
 * *vmware*, is a VMWare SVGA-II compatible adapter.
 * *qxl*, is the QXL paravirtualized graphics card. Selecting this also
 qemu: using cirrus considered harmful], e.g., if using Windows XP or earlier
 * *vmware*, is a VMWare SVGA-II compatible adapter.
 * *qxl*, is the QXL paravirtualized graphics card. Selecting this also

-enables SPICE for the VM.
+enables https://www.spice-space.org/[SPICE] (a remote viewer protocol) for the
+VM.

 
 You can edit the amount of memory given to the virtual GPU, by setting
 the 'memory' option. This can enable higher resolutions inside the VM,
 
 You can edit the amount of memory given to the virtual GPU, by setting
 the 'memory' option. This can enable higher resolutions inside the VM,


@@ -753,6 +769,28 @@ footnote:[Looking Glass: https://looking-glass.hostfission.com/] project,
 which enables high performance, low-latency display mirroring between
 host and guest.
 
 which enables high performance, low-latency display mirroring between
 host and guest.
 

+[[qm_audio_device]]
+Audio Device
+~~~~~~~~~~~~
+
+To add an audio device run the following command:
+
+----
+qm set <vmid> -audio0 device=<device>
+----
+
+Supported audio devices are:
+
+* `ich9-intel-hda`: Intel HD Audio Controller, emulates ICH9
+* `intel-hda`: Intel HD Audio Controller, emulates ICH6
+* `AC97`: Audio Codec '97, useful for older operating systems like Windows XP
+
+NOTE: The audio device works only in combination with SPICE. Remote protocols
+like Microsoft's RDP have options to play sound. To use the physical audio
+device of the host use device passthrough (see
+xref:qm_pci_passthrough[PCI Passthrough] and
+xref:qm_usb_passthrough[USB Passthrough]).
+

 [[qm_startup_and_shutdown]]
 Automatic Start and Shutdown of Virtual Machines
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 [[qm_startup_and_shutdown]]
 Automatic Start and Shutdown of Virtual Machines
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@@ -797,6 +835,70 @@ start after those where the parameter is set. Further, this parameter can only
 be enforced between virtual machines running on the same host, not
 cluster-wide.
 
 be enforced between virtual machines running on the same host, not
 cluster-wide.
 

+[[qm_spice_enhancements]]
+SPICE Enhancements
+~~~~~~~~~~~~~~~~~~
+
+SPICE Enhancements are optional features that can improve the remote viewer
+experience.
+
+To enable them via the GUI go to the *Options* panel of the virtual machine. Run
+the following command to enable them via the CLI:
+
+----
+qm set <vmid> -spice_enhancements foldersharing=1,videostreaming=all
+----
+
+NOTE: To use these features the <<qm_display,*Display*>> of the virtual machine
+must be set to SPICE (qxl).
+
+Folder Sharing
+^^^^^^^^^^^^^^
+
+Share a local folder with the guest. The `spice-webdavd` daemon needs to be
+installed in the guest. It makes the shared folder available through a local
+WebDAV server located at http://localhost:9843.
+
+For Windows guests the installer for the 'Spice WebDAV daemon' can be downloaded
+from the
+https://www.spice-space.org/download.html#windows-binaries[official SPICE website].
+
+Most Linux distributions have a package called `spice-webdavd` that can be
+installed.
+
+To share a folder in Virt-Viewer (Remote Viewer) go to 'File -> Preferences'.
+Select the folder to share and then enable the checkbox.
+
+NOTE: Folder sharing currently only works in the Linux version of Virt-Viewer.
+
+CAUTION: Experimental! Currently this feature does not work reliably.
+
+Video Streaming
+^^^^^^^^^^^^^^^
+
+Fast refreshing areas are encoded into a video stream. Two options exist:
+
+* *all*: Any fast refreshing area will be encoded into a video stream.
+* *filter*: Additional filters are used to decide if video streaming should be
+  used (currently only small window surfaces are skipped).
+
+A general recommendation if video streaming should be enabled and which option
+to choose from cannot be given. Your mileage may vary depending on the specific
+circumstances.
+
+Troubleshooting
+^^^^^^^^^^^^^^^
+
+.Shared folder does not show up
+
+Make sure the WebDAV service is enabled and running in the guest. On Windows it
+is called 'Spice webdav proxy'. In Linux the name is 'spice-webdavd' but can be
+different depending on the distribution.
+
+If the service is running, check the WebDAV server by opening
+http://localhost:9843 in a browser in the guest.
+
+It can help to restart the SPICE session.

 
 [[qm_migration]]
 Migration
 
 [[qm_migration]]
 Migration


@@ -1091,6 +1193,28 @@ It will be called during various phases of the guests lifetime.
 For an example and documentation see the example script under
 `/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
 
 For an example and documentation see the example script under
 `/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
 

+[[qm_hibernate]]
+Hibernation
+-----------
+
+You can suspend a VM to disk with the GUI option `Hibernate` or with
+
+ qm suspend ID --todisk
+
+That means that the current content of the memory will be saved onto disk
+and the VM gets stopped. On the next start, the memory content will be
+loaded and the VM can continue where it was left off.
+
+[[qm_vmstatestorage]]
+.State storage selection
+If no target storage for the memory is given, it will be automatically
+chosen, the first of:
+
+1. The storage `vmstatestorage` from the VM config.
+2. The first shared storage from any VM disk.
+3. The first non-shared storage from any VM disk.
+4. The storage `local` as a fallback.
+

 Managing Virtual Machines with `qm`
 ------------------------------------
 
 Managing Virtual Machines with `qm`
 ------------------------------------
 


@@ -1200,6 +1324,10 @@ There are a few snapshot related properties like `parent` and
 relationship between snapshots. `snaptime` is the snapshot creation
 time stamp (Unix epoch).
 
 relationship between snapshots. `snaptime` is the snapshot creation
 time stamp (Unix epoch).
 

+You can optionally save the memory of a running VM with the option `vmstate`.
+For details about how the target storage gets chosen for the VM state, see
+xref:qm_vmstatestorage[State storage selection] in the chapter
+xref:qm_hibernate[Hibernation].

 
 [[qm_options]]
 Options
 
 [[qm_options]]
 Options