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qm: add sub-headings to hard disk section

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and references

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
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Thomas Lamprecht 2019-11-06 18:39:02 +01:00
parent 9ea21953f6
commit 3dbe1daabf
1 changed files with 17 additions and 1 deletions
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@ -150,6 +150,9 @@ one want's to pass through PCIe hardware.
Hard Disk Hard Disk
~~~~~~~~~ ~~~~~~~~~
[[qm_hard_disk_bus]]
Bus/Controller
^^^^^^^^^^^^^^
Qemu can emulate a number of storage controllers: Qemu can emulate a number of storage controllers:
* the *IDE* controller, has a design which goes back to the 1984 PC/AT disk * 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 It has been superseded by the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. VirtIO SCSI Controller, in terms of features.
[thumbnail="screenshot/gui-create-vm-hard-disk.png"] [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 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 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 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 * the *VMware image format* only makes sense if you intend to import/export the
disk image to other hypervisors. 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 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 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 means that the guest system will be notified that a write is complete when each
@ -215,6 +225,9 @@ 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 `zfspool`, so adding a disk image to other storages when the VM has replication
configured requires to skip replication for this disk image. 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 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* {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 set and a _TRIM_-enabled guest OS footnote:[TRIM, UNMAP, and discard
@ -232,7 +245,10 @@ 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. 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. 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 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 *VirtIO* controller, or with the *SCSI* controller, when the emulated controller
type is *VirtIO SCSI single*. type is *VirtIO SCSI single*.