Addition of a storage unit to the Datacenter

[miranpiscanc]

Good morning, everyone. I am unable to connect a new external 1TB SSD to use it as storage for a new VM.
In this section, it can be seen that the SSD is connected to the NUC



So, I go here.


I press the Additional button


But then it doesn't give me the option to select the 1TB USB SSD.



What am I forgetting? Thank you all for the support

 

[cheiss]

Hi,

you need to first format the drive - by clicking Wipe Disk in the Disks dialog. This will obviously destroy all data on that disk, so be sure that you a) don't need anything off it anymore and b) you select the correct one!

Then, you can go to Disks > LVM (or Disks > LVM-thin) and create a new volume group (or thinpool) on it. That also creates the corresponding storage entry, if you keep the Add Storage checkbox selected.

 

[miranpiscanc]

Ok, thanks. The disk is empty, formatted in Windows, so I assumed that was enough. I didn’t know about the WIPE function—what does it do? Thanks.

 

[cheiss]

The Wipe Disk really wipes the disk, i.e. clears everything including the partition table.
LVM and LVM-thin don't need a partition table, so they just use the whole disk.

 

[miranpiscanc]

Thank you for the clarification. It’s working now, and I have a new 1TB storage available. My next question is: can I use the MOVE STORAGE function to transfer a VM from one destination to this newly created one? I assume it’s better to shut down the machine first, or does Proxmox automatically shut it down? Thanks

 

[cheiss]

Actually, storage migration can be done live while the VM is running, without needing to shut it down.
You can go to the Hardware tab of the VM, select the disk to move and then click on Disk Action > Move Storage above. There you can simply select your new storage.

 

[miranpiscanc]

I have another issue. I added a 500GB SSD and made it visible to Proxmox. I would like to switch the current disk to the new SSD, but it returns an error. I see there’s a difference in gigabytes, but the VM is only using 300GB out of the 500GB. I also tried the clone function, but the same problem occurs—it creates an error. How can I reduce the current disk space to be able to switch the disks? I assume this is the issue

 

[cheiss]

The error has nothing to do with the storage size, but rather the underlying mechanism for async I/O used by QEMU.
io_uring is not supported for (thick) LVM volumes, as there have been issues in the past with that combination.

You can change it by editing the disk, under the advanced option there is a dropdown Async IO. Choose either native or threads, both should work fine for your case.
This unfortunaly does require a reboot (either poweroff+poweron or reboot via the PVE interface) after changing.

 

[miranpiscanc]

Ok, thanks for the explanation. Fortunately, it’s not a space issue. But if I may ask for further help: I can’t find the dropdown menu to change the Async IO value. Where exactly is it located? Thanks.

 

[Tharos47]

You can double click on the disk in the hardware tab and select "advanced" to access more options.

 

[miranpiscanc]

Ok, thanks, in fact, it’s working better now. I tried moving the disk, now the problem is space. How can I reduce the source? Thanks.