On 19/07/16 09:52, Alexis HAUSER wrote: Yes, each VM disk is a Logical Volume on that LUN. Sounds like a possible networking problem. Have you assigned IP addresses to the storage interfaces on this new host? If you're using VLANs, are they set up correctly on your switch ports for the SAN network? Alex -- This message is intended only for the addressee and may contain confidential information. Unless you are that person, you may not disclose its contents or use it in any way and are requested to delete the message along with any attachments and notify us immediately. This email is not intended to, nor should it be taken to, constitute advice. The information provided is correct to our knowledge & belief and must not be used as a substitute for obtaining tax, regulatory, investment, legal or any other appropriate advice. "Transact" is operated by Integrated Financial Arrangements Ltd. 29 Clement's Lane, London EC4N 7AE. Tel: (020) 7608 4900 Fax: (020) 7608 5300. (Registered office: as above; Registered in England and Wales under number: 3727592). Authorised and regulated by the Financial Conduct Authority (entered on the Financial Services Register; no. 190856).

On 19/07/16 10:38, Alexis HAUSER wrote: I don't understand. iSCSI is a network storage protocol. What do you mean by "I access it directly"? When you set up the first host with an iSCSI storage domain, you would have had to point it to an IP address, "discover" the LUNs and then attach to them. This sets up the domain. On the second host, to access iSCSI storage you will have to have an interface (defined in "Networks" in oVirt) that can connect to the same IP and port the first host used. Alex -- This message is intended only for the addressee and may contain confidential information. Unless you are that person, you may not disclose its contents or use it in any way and are requested to delete the message along with any attachments and notify us immediately. This email is not intended to, nor should it be taken to, constitute advice. The information provided is correct to our knowledge & belief and must not be used as a substitute for obtaining tax, regulatory, investment, legal or any other appropriate advice. "Transact" is operated by Integrated Financial Arrangements Ltd. 29 Clement's Lane, London EC4N 7AE. Tel: (020) 7608 4900 Fax: (020) 7608 5300. (Registered office: as above; Registered in England and Wales under number: 3727592). Authorised and regulated by the Financial Conduct Authority (entered on the Financial Services Register; no. 190856).

On 19/07/16 11:13, Alexis HAUSER wrote: It knows there there are volume groups from the database. You are correct, in that it cannot access the VGs/LVs. I'm still finding this hard to understand. If you are using iSCSI, you /are/ using a server (called the "Target" in SCSI speak). Is the iSCSI storage actually on the first host? How did you actually do the discovery and assign the LUNs? In the storage domain properties you should be able to see the IP and port of the Targets, something like "iqn.2012-02:foo-target1,192.168.10.10,3260", and you need to ensure the second host can reach that IP and port to be able to see the storage. Multipath should not make any difference right now, but in order to use it effectively you should probably set up an iSCSI bond. The requirement for multipath to work properly is that the two physical interfaces on the host and initiator are in different IP subnets (and should ideally travel via different switches but that is not a hard requirement). If you only have one physical interface on each host, there's not much point doing multipath, as you don't stand to gain any performance or resilience. Cheers Alex -- This message is intended only for the addressee and may contain confidential information. Unless you are that person, you may not disclose its contents or use it in any way and are requested to delete the message along with any attachments and notify us immediately. This email is not intended to, nor should it be taken to, constitute advice. The information provided is correct to our knowledge & belief and must not be used as a substitute for obtaining tax, regulatory, investment, legal or any other appropriate advice. "Transact" is operated by Integrated Financial Arrangements Ltd. 29 Clement's Lane, London EC4N 7AE. Tel: (020) 7608 4900 Fax: (020) 7608 5300. (Registered office: as above; Registered in England and Wales under number: 3727592). Authorised and regulated by the Financial Conduct Authority (entered on the Financial Services Register; no. 190856).

On 19/07/16 15:22, Alexis HAUSER wrote: If it offers iSCSI, it is indeed a "Target". It's effectively a server as it's offering up a service on the network! That does explain my confusion though... Normally you should not have to do that. It could be that it was not allowed access, and you'd have to leave it a while for the host to retry. At least you have it working now! Maintenance mode will migrate any running VMs off that host and enable you to do some tasks (including the ones you mention) that you can't do when it's running VMs. I believe it stops certain services as well, not sure which ones. It's perfectly safe and routine thing to do in RHEV/oVirt. Cheers Alex -- This message is intended only for the addressee and may contain confidential information. Unless you are that person, you may not disclose its contents or use it in any way and are requested to delete the message along with any attachments and notify us immediately. This email is not intended to, nor should it be taken to, constitute advice. The information provided is correct to our knowledge & belief and must not be used as a substitute for obtaining tax, regulatory, investment, legal or any other appropriate advice. "Transact" is operated by Integrated Financial Arrangements Ltd. 29 Clement's Lane, London EC4N 7AE. Tel: (020) 7608 4900 Fax: (020) 7608 5300. (Registered office: as above; Registered in England and Wales under number: 3727592). Authorised and regulated by the Financial Conduct Authority (entered on the Financial Services Register; no. 190856).