On Tue, Jun 14, 2016 at 12:01:52PM +0100, Daniel P. Berrange wrote:
On Tue, Jun 14, 2016 at 12:50:09PM +0200, Kashyap Chamarthy wrote:
Summary -------
It seems like libvirt is generating the same QEMU drive host alias ('drive-virtio-disk%d') for different two disk labels (vdb, vdb1).
[Refer the contextual root cause analysis discussion at the end with Laine & Peter.]
Let's take a quick example to demonstrate the issue.
On a guest that is shut down, attach a couplee of disks with labels 'vdb', and 'vdb1'
$ sudo virsh attach-disk cvm1 \ /export/vmimages/1.raw vdb --config
$ sudo virsh attach-disk cvm1 \ /export/vmimages/1.raw vdb1 --config
That second command is user error - hotplugging a disk partition is nonsensical, except with Xen which allows that for paravirtualized disks. We should reject such disk names with an error right away in all other cases.
Okay, filed this upstream bug: https://bugzilla.redhat.com/show_bug.cgi?id=1346265 -- Disallow disk hot-plugging with invalid target labels (e.g. disk partition number for non-paravirt disks) I realized supplying disk partition numbers as targets is not sensible, but virDiskNameParse() parses partition numbers too: $ less -N src/util/virutil.c [...] 543 /* Translates a device name of the form (regex) /^[fhv]d[a-z]+[0-9]*$/ 544 * into the corresponding index and partition number 545 * (e.g. sda0 => (0,0), hdz2 => (25,2), vdaa12 => (26,12)) 546 * @param name The name of the device 547 * @param disk The disk index to be returned 548 * @param partition The partition index to be returned 549 * @return 0 on success, or -1 on failure 550 */ 551 int virDiskNameParse(const char *name, int *disk, int *partition) 552 { [...] -- /kashyap