Am 06.12.2010 12:29, schrieb Alexander Graf: > On 06.12.2010, at 11:49, Vandeir Eduardo wrote: >> >> I have a KVM guest machine, lets name it VMTEST, >> using an iSCSI LUN as a virtio device. Something like this: >> >> <disk type='block' device='disk'> >> <driver name='qemu' type='raw' cache='none'/> >> <source >> dev='/dev/disk/by-path/ip-w.x.y.z:3260-iscsi-iqn.2010-10.br.furb.inf:disk0-lun-4'/> >> <target dev='vda' bus='virtio'/> >> </disk> >> >> On iSCSI server, if I resize this LUN, this resize is detected >> on KVM host, but not on the VMTEST. The device resize is only >> detected if I restart VMTEST. Is there a way to make VMTEST detect >> the /dev/vda resize without restarting it? >> >> On VMTEST I already tried commands like partprobe /dev/vda, >> hdparm -z /dev/vda and blockdev --rereadpt /dev/vda, but none of >> was capable to detect the block device (/dev/vda) resize. > > The probing of an image is only done at initialization time of the block > backend driver, which in your case is the bootup. The only chance you have of > reevaluating it would be to hot-add another virtio device with the resized > image. > > Alternatively, you could also try to write a patch for reevaluation plumbing, > so that the hba emulation layer can trigger reevaluation in the disk layer.
This is basically online disk resizing, which we have discussed in the past and which I think we want to have for virtio-blk eventually, but currently it's supported neither in the host qemu nor in the guest kernel. Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
