On Tue, Jul 28, 2020 at 8:56 AM Nick Kas via Users <users@ovirt.org> wrote:
Hello evryone,
setup ovirt 4.4.1 on CentOS 8.2 as an experiment, and I am trying to get an iSCSI domain working but have issues. The little experimental cluster has 3 hosts. There is an ovirtmgmt network on the default vlan, and two iSCSI network (172.27.0/1.X) with vlans 20/21. ovirtmgmt has all the functions (Data, display, migration etc), and the iSCSI networks nothing yet, and they are not set as required.
The SAN device is already serving a few iSCSI volumes to a vmware cluster, so I know things are fine on this end. It has two controllers, and four NICs per controller so a total of 8 NICs, half of the NICS per controller on 172.27.0.X and half on 172.27.1.X.

When I create the iSCSI domain, I login to only one of the targets, and add the Volume, all is good and I can use the disc fine.
However when I login to more than one of the targets, then I start having issues with the Volume. Even when I enabled multipath in the cluster, and I created a single multipath by selecting both of the 172.27.0/1.X networks, and all the targets, the end result was the same. The hosts have difficulty accessing the volume, they may even swing between 'non-operational' and 'up' if I transfer data to the volume. When I ssh to the hosts and i check things in the command line I also get inconsistent results between hosts, and blocks that appear with lsblk when I first setup iSCSI have dissapeared after I try to actively use the volume.
maybe /var/log/vdsm/vdsm.log could tell more.

I am new to iSCSI so I am not sure how to debug this. I am not sure if my multipath configuration is correct or not. The documentation on this part was not very detailed. I also tried to remove the domain, and try to experiment with mounting the iSCSI volume from the command line, but I cannot even discover the target from the command line, which is very bizarre. The command
iscsiadm --mode discovery --target sendtargets --portal 172.27.0.55 --discover
you are mixing "--target" with "--type", should be:
iscsiadm --mode discovery --type sendtargets --portal 172.27.0.55 --interface default
returns the message 'iscsiadm: cannot make connection to 172.27.0.55: No route to host'. Yet through ovirt, and if I select only one target, everything work fine!

Any suggestions on how to start debugging this would really be appreciated.
_______________________________________________
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-leave@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/
List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/N5DNXQ5MAMPXMA3LOHM4RHUZLYKUUMLO/