[SOLVED] Proxmox VE - VM Disk Hot-Add Not Detected by Guest OS

[pulipulichen]

Hello everyone,

I would like to ask about disk expansion behavior in Proxmox VE.

Currently, I am testing adding a second disk (disk2) while the VM is running (online). However, regardless of whether the guest OS is Linux or Windows, the newly added disk is not detected immediately inside the guest system (see attached screenshot).

I would like to confirm:
1. Does Proxmox VE support hot-add (online) disk expansion for VMs?
2. Is it required to power off the VM before adding a new disk for it to take effect?
3. Could this be related to the disk controller type (e.g., VirtIO SCSI / SATA / IDE)?
4. Is a manual rescan required inside the guest OS?

I would appreciate clarification on the correct procedure. Thank you.

 

[JeanL]

Hi,

Since your hard disk (ide1) is orange, it's not plugged, you need to stop/start the VM to take effect; and it's most likely due to the fact that you are using the "LSI" controller with IDE disk (if I remember correctly, hot plug was never officially supported on IDE devices).

Since PVE8 (if I'm not mistaken), the default is "VirtIO SCSI single" with an SCSI disk.

Best regards,

 

[Saron]

Hotplug is supported in Proxmox VE. In your VMs settings you can configure which hardware types have hotplug enabled (for disks its enabled by default). For IDE disks hotplug seems not to work and for SCSI disks this only seems to work with VirtIO SCSI controllers. I tried to add SCSI disks with LSI controller for a Linux VM and the guest Kernel is not recognizing the devices.
Normally the guest OS detects new disks automatically with the right configuration. If you want to change your controller type you have reboot the VM. For a windows setup look at this: https://pve.proxmox.com/wiki/Paravirtualized_Block_Drivers_for_Windows

 

[pulipulichen]

Hotplug is supported in Proxmox VE. In your VMs settings you can configure which hardware types have hotplug enabled (for disks its enabled by default). For IDE disks hotplug seems not to work and for SCSI disks this only seems to work with VirtIO SCSI controllers. I tried to add SCSI disks with LSI controller for a Linux VM and the guest Kernel is not recognizing the devices.
Normally the guest OS detects new disks automatically with the right configuration. If you want to change your controller type you have reboot the VM. For a windows setup look at this: https://pve.proxmox.com/wiki/Paravirtualized_Block_Drivers_for_Windows

Thank you both for the guidance! I didn't realize that IDE disks behave so differently from SCSI when it comes to hot-plugging. I've definitely learned something new today.