Maybe my question is difficult, though it should not be. "Virsh attach-disk" seems to be poorly documented. One correction: this was definitely not "my last problem" - it was only the latest. :-) Now I continue configuring my kvm system with the "traditional" way - one filesystem per guest. - Jussi On 23.4.2011 17.58, Jussi Hirvi wrote: > Greetings, list! > > I hope you forgive cross-posting - I only now found this list. > > I am in the process of configuring a KVM stack of about 8 vms. Mostly I > am concerned about performance, as there will be a lot of I/O. > > My last problem is this: I try to add a fresh, unformatted disk > partition to a KVM guest. I follow the directions given here: > > http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html-single/Virtualization/index.html#proc-Virtualization-Adding_storage_devices_to_guests-Adding_physical_block_devices_to_virtualized_guests > > First I check that the module acpiphp is present on the guest. It is. > > On the host I write: > > virsh attach-disk test1 /dev/sdb1 sda --driver tap --mode shareable > > - test1 is my guest domain > - /dev/sdb1 is the name of the unformatted partition on the host > - sda is what it is supposed to be called on the guest (the name is > unused on the guest) > - the example in RHEL Virtualization guide says "--mode readonly". This > does not sound right for a hard disk; hence I try "--mode shareable"; > the error (see below) however is the same, whichever I use > > Now, the command above produces this error. I find no google results > with this error text. Can someone tell, what causes the error? > > > > error: Failed to attach disk error: operation failed: adding scsi > > > disk controller failed: type scsi not a hotpluggable PCI device. > > > failed to add if=scsi > > I found a post (2009, on fedora-virt list), which is relevant: > > http://www.redhat.com/archives/fedora-virt/2009-December/msg00032.html > > Otherwise, I have found almost nothing! > > BTW, I can attach a disk to the KVM guest, using a virtio driver: > > > > [root at 113 info]# virsh attach-disk test1 /dev/sdd1 vdb > > > --driver virtio --mode shareable > > Disk attached successfully > > I have not seen any mention anywhere about using virtio drivers like > this. And the problem with this is that the new disk does not survive > guest reboot. At guest startup virsh complains about the virtio drivers. > > - Jussi > -- Jussi Hirvi * Green Spot Suvilahdenkatu 1 B 78 * 00500 Helsinki * Finland Tel. +358 9 493 981 * Mobile +358 40 771 2098 (only sms) jussi.hirvi at greenspot.fi * http://www.greenspot.fi