[et-mgmt-tools] What are Xen CDROM limits?

Cole Robinson crobinso at redhat.com
Tue Sep 23 13:46:41 UTC 2008

Alexander Todorov wrote:
> Hash: SHA512
> Hi all,
> I need to be able to attach multiple ISO images to a Xen DomU (hvm) at the same
> time. Using the UI of virt-manager I was able to attach 3 ISO files as IDE CDROM
> devices. The 4th failed. IIRC VMWare is capable of more.
> Is 3 the limit and if yes why? Is this limit higher with KVM or other
> virtualization technology?

Xen uses a forked qemu for HVM device emulation. At least on
RHEL, the version of qemu they are roughly using only allows
attaching IDE disks, which is limited to four max.

Newer qemu (and kvm by extension) allow attaching scsi disks
and cdroms, which support a much larger number of devices.
This is available in F9 and later.

There is support in libvirt for adding scsi cdroms, though
the option isn't listed in virt-manager yet.

Hope that helps,

More information about the et-mgmt-tools mailing list