<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Sep 8, 2020 at 8:43 AM Daniel P. Berrangé <<a href="mailto:berrange@redhat.com">berrange@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Tue, Sep 08, 2020 at 08:19:21AM -0400, Alexander Wels wrote:<br>
> Hi,<br>
> <br>
> I am working on a project, and one of the requirements is that I can<br>
> hotplug a large number of disks. Think several dozens to potentially 100+.<br>
> The guest OS will be some linux flavor so it should have no problem with a<br>
> large number of disks.<br>
> <br>
> During my experimentation I quickly ran into the "No available PCI slots"<br>
> limit. I found <a href="https://libvirt.org/pci-hotplug.html" rel="noreferrer" target="_blank">https://libvirt.org/pci-hotplug.html</a> explaining to me why<br>
> the limit is there. Now I could add a bunch of pcie-root-ports ahead of<br>
> time, but there is likely a limit to that as well. So before I go down some<br>
> crazy paths, I figured I would ask on here if there is a better plan than<br>
> adding a bunch of root ports for adding a large number of hotplugged disks?<br>
<br>
While you can add extra PCI bridges, I'd suggest using virtio-scsi<br>
instead<br>
<br>
These blog posts should serve as warning about some of the limits<br>
you'll hit:<br>
<br>
<a href="https://rwmj.wordpress.com/2017/04/25/how-many-disks-can-you-add-to-a-virtual-linux-machine/" rel="noreferrer" target="_blank">https://rwmj.wordpress.com/2017/04/25/how-many-disks-can-you-add-to-a-virtual-linux-machine/</a><br>
<a href="https://rwmj.wordpress.com/2017/04/28/how-many-disks-can-you-add-to-a-virtual-linux-machine-contd/" rel="noreferrer" target="_blank">https://rwmj.wordpress.com/2017/04/28/how-many-disks-can-you-add-to-a-virtual-linux-machine-contd/</a><br>
<br></blockquote><div><br></div><div>Thanks I read those. my absolute upper limit is going to be in the 100ish range so I should be good there. I will investigate virtio-scsi.<br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Regards,<br>
Daniel<br>
-- <br>
|: <a href="https://berrange.com" rel="noreferrer" target="_blank">https://berrange.com</a>      -o-    <a href="https://www.flickr.com/photos/dberrange" rel="noreferrer" target="_blank">https://www.flickr.com/photos/dberrange</a> :|<br>
|: <a href="https://libvirt.org" rel="noreferrer" target="_blank">https://libvirt.org</a>         -o-            <a href="https://fstop138.berrange.com" rel="noreferrer" target="_blank">https://fstop138.berrange.com</a> :|<br>
|: <a href="https://entangle-photo.org" rel="noreferrer" target="_blank">https://entangle-photo.org</a>    -o-    <a href="https://www.instagram.com/dberrange" rel="noreferrer" target="_blank">https://www.instagram.com/dberrange</a> :|<br>
<br>
</blockquote></div></div>