I've configured a libvirt storage pool using an iscsi target from a Sun 7310 storage appliance and am using the LUNs in this target as volumes for my KVM guests. The setup is very similar to what Daniel covered in a recent blog posting: http://berrange.com/posts/2010/05/05/provisioning-kvm-virtual-machines-on... It works great, but I can't figure out how to match the volume names & path IQNs within the storage pool to the GUIDs on the target. For example, here's what I see when I use the vol-info command: # virsh vol-list kvm-target Name Path ----------------------------------------- 6.0.0.0 /dev/disk/by-path/ip-X.X.X.X:3260-iscsi-iqn.1986-03.com.sun:02:<snipped>-lun-0 6.0.0.1 /dev/disk/by-path/ip-X.X.X.X:3260-iscsi-iqn.1986-03.com.sun:02:<snipped>-lun-1 The IQN matches the targets IQN, but when I browse the LUNs from the storage system I do not see a way to determine which of them is *-lun-0 and which is *-lun-1, I only see a GUID and an alias name that I created. Is there any way to get that info (or something else that will do the job) from a virsh command?

On 06/16/2010 01:41 PM, Daniel P. Berrange wrote: > On Wed, Jun 16, 2010 at 01:20:02PM -0400, Tom Georgoulias wrote: >> I've configured a libvirt storage pool using an iscsi target from a Sun >> 7310 storage appliance and am using the LUNs in this target as volumes >> for my KVM guests. The setup is very similar to what Daniel covered in >> a recent blog posting: >> >> http://berrange.com/posts/2010/05/05/provisioning-kvm-virtual-machines-on... >> >> It works great, but I can't figure out how to match the volume names& >> path IQNs within the storage pool to the GUIDs on the target. >> >> For example, here's what I see when I use the vol-info command: >> >> # virsh vol-list kvm-target >> Name Path >> ----------------------------------------- >> 6.0.0.0 >> /dev/disk/by-path/ip-X.X.X.X:3260-iscsi-iqn.1986-03.com.sun:02:<snipped>-lun-0 >> 6.0.0.1 >> /dev/disk/by-path/ip-X.X.X.X:3260-iscsi-iqn.1986-03.com.sun:02:<snipped>-lun-1 >> >> The IQN matches the targets IQN, but when I browse the LUNs from the >> storage system I do not see a way to determine which of them is *-lun-0 >> and which is *-lun-1, I only see a GUID and an alias name that I created. >> >> Is there any way to get that info (or something else that will do the >> job) from a virsh command? > > Nothing at this time. If you weren't using libvirt, how would you discover > the GUIDs on the Linux client ? If there is a way to get these from sysfs > or elsewhere, we can wire it up in libvirt to the<key> element in the XML > for the volume. I just don't know how yet... That's a good question, I tried to figure out a way to do so with iscsiadm but didn't find anything. But I'm glad you mentioned the sysfs angle, it prodded me in the right direction and I think I found something to work with. # udevinfo -a -p $(udevinfo -q path -n /dev/sdg) looking at device '/block/sdg': KERNEL=="sdg" SUBSYSTEM=="block" SYSFS{stat}==" 20458 183 451623 17494 27820 11891 4508156 552205 0 70083 569695" SYSFS{size}=="41943040" SYSFS{removable}=="0" SYSFS{range}=="16" SYSFS{dev}=="8:96" looking at parent device '/devices/platform/host6/session2/target6:0:0/6:0:0:0': ID=="6:0:0:0" BUS=="scsi" DRIVER=="sd" SYSFS{ioerr_cnt}=="0x3" SYSFS{iodone_cnt}=="0xbcb4" SYSFS{iorequest_cnt}=="0xbcb4" SYSFS{iocounterbits}=="32" SYSFS{timeout}=="60" SYSFS{state}=="running" SYSFS{rev}=="1.0 " SYSFS{model}=="Sun Storage 7310" SYSFS{vendor}=="SUN " SYSFS{scsi_level}=="6" SYSFS{type}=="0" SYSFS{queue_type}=="none" SYSFS{queue_depth}=="32" SYSFS{device_blocked}=="0" looking at parent device '/devices/platform/host6/session2/target6:0:0': ID=="target6:0:0" BUS=="" DRIVER=="" looking at parent device '/devices/platform/host6/session2': ID=="session2" BUS=="" DRIVER=="" looking at parent device '/devices/platform/host6': ID=="host6" BUS=="" DRIVER=="" looking at parent device '/devices/platform': ID=="platform" BUS=="" DRIVER=="" # scsi_id -g -x -s /block/sdg ID_VENDOR=SUN ID_MODEL=Sun_Storage_7310 ID_REVISION=1.0 ID_SERIAL=3600144f0a523738a00004c18ec990004 ID_TYPE=disk ID_BUS=scsi The GUID for this LUN is "600144F0A523738A00004C18EC990004". That's the same number that is used in the ID_SERIAL, except that it has a 3 prepended on it. So now I can tell which LUN is really volume 6.0.0.0.

I discovered you can get the info from UDEV, eg if libvirt reports a volume '/dev/sde' you can query against the block device path # scsi_id --export --whitelisted /dev/sde ID_VENDOR=QNAP ID_VENDOR_ENC=QNAP ID_MODEL=iSCSI_Storage ID_MODEL_ENC=iSCSI\x20Storage ID_REVISION=3.1 ID_TYPE=disk ID_SERIAL=36001405e61fd1a5d6f1dd4d66d9630d2 ID_SERIAL_SHORT=6001405e61fd1a5d6f1dd4d66d9630d2 The ID_SERIAL field should be what you what IIUC We'll see about making libvirt report this value directly as the 'key' for the volume