Re: [libvirt-users] Connect libvirt to iSCSI target

On 2013–12–21 John Ferlan wrote: > On 12/17/2013 07:13 PM, Marco wrote: >> Hi! >> >> I'm new to libvirt and face problems connecting to an iSCSI target. >> What I intend to do is to connect libvirt (I tried virt-manager and >> virsh) to an iSCSI target and then boot from the LUNs which contain >> the VMs. >> >> I followed the documentation¹ but got stuck at section 12.1.5.4.3. >> >> 1) >> virsh pool-define-as \ >> --name foo \ >> --type iscsi \ >> --source-host vmhost \ >> --source-dev iqn.2013-11.vmhost:vmpool \ >> --target /dev/disk/by-path >> >> 2) >> virsh pool-start foo >> error: Failed to start pool foo >> error: internal error: cannot find session >> >> virsh -c qemu:///system pool-start foo >> error: Failed to start pool foo >> error: internal error: cannot find session >> > > I'm assuming 'vmhost' is actually some valid IP Address/Name that you're > just using here to hide from the world your actual iSCSI tgt server. > Don't forget that the 'source-host' may be listed as > 'host1.example.com'; however, the iqn has 'com.example.host1'. IOW - > reversed... It's a test setup and I don't use a FQDN. > Have you looked at http://libvirt.org/formatstorage.html ? I did, indeed. > There's an example there of output that works for me. For me it does not. > Use virsh pool-dumpxml <pool> > to view the XML... Here's my XML which is directly taken from the manual. I only changed the host name to “freenas” and the device path. <pool type='iscsi'> <name>virtimages</name> <uuid>347feb68-7e11-4f2b-ba82-ada027296fb0</uuid> <capacity unit='bytes'>0</capacity> <allocation unit='bytes'>0</allocation> <available unit='bytes'>0</available> <source> <host name='freenas'/> <device path='iqn.2013-11.freenas:vmpool'/> </source> <target> <path>/dev/disk/by-path</path> <permissions> <mode>0755</mode> <owner>-1</owner> <group>-1</group> </permissions> </target> </pool> > Also, do you need to authenticate to the iSCSI target? Not yet. To rule out authentication issues for testing I turned off authentication. > The iscsiadm will use '/etc/iscsi/iscsid.conf'. See the > node.session.auth.{authmethod | username | password} fields, so > while iscsiadm may work, when libvirt goes to connect it fails. Thanks for pointing that out, but I don't think it's the case here. > Looking at the output in the system messages > log may help (for my f19 /var/log/messages). The log of a failed virsh pool-start virtimages can be found here http://dpaste.com/1518444/ Most notable is I assume: libvirtd[8028]: internal error: Child process (/usr/bin/iscsiadm --mode session) unexpected exit status 21

>From “man iscsiadm”: 21 ISCSI_ERR_NO_OBJS_FOUND - no records/targets/sessions/portals found to execute operation on. If I run “iscsiadm --mode session” in the console, I indeed get and error: iscsiadm: No active sessions. Do I need to create a session or setup libvert to do that before iSCSI is supposed to work? The log shows that libvirt is able to connect to the target: iscsid: Connection85:0 to [target: iqn.2013-11.freenas:vmpool, portal: 10.0.10.23,3260] through [iface: libvirt-iface-04d9ea67] is operational now > You may also find if you have selinux enabled as Enforcing there could > be more configuration that you need (if the iSCSI tgtd is local). > Setting up a label on the file - something I'm not an expert at... selinux is not used. > Another tool to try is 'iscsi-ls' from package 'libiscsi-utils' > > iscsi-ls -s -i iqn.2013-11.vmhost:vmpool \ > iscsi://<username>%<password>@<ipAddr>:3260 This succeeds: iscsi-ls -s -i iqn.2013-11.freenas:vmpool iscsi://freenas Target:iqn.2013-11.freenas:vmpool Portal:10.0.10.23:3260,1 Lun:0 Type:DIRECT_ACCESS (Size:9G) […] > If you need to authenticate, then set up a secret to the iSCSI server, > see http://libvirt.org/formatsecret.html for an example. If the simple setup is working I'll add authentication but for the moment I try to keep is as simple as possible. To rule out issues with the iSCSI target I manually tested using “iscsiadm” and VirtualBox which both succeeded without any session errors. Thanks for your quick response. Best regards Marco _______________________________________________ libvirt-users mailing list libvirt-users(a)redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users