[ovirt-users] iSCSI connection to a LUN - EMC CX4-120 - Login OK but no LUN

[Nicolas Ecarnot]

Le 21/10/2014 12:18, Nicolas Ecarnot a écrit :
> Hi,
>
> Setting up our third oVirt infra, we are now connecting it to an EMC
> CX4-120 SAN.
> On this SAN, we have set up a classical storage group, added the
> authorized hosts, registered them.
>
> On the oVirt side, we want to create the first master storage domain and
> so we give the GUI the right SAN ip, and the iSCSI connection is working.
>
> We see appearing the two virtual IP of the storage processors (A and B),
> and the login button reacts well, no error appears.
> But no LUN shows up at this point.
>
> Looking at the hosts used by this connection, it appears that the iSCSI
> connection worked well, and that the LUN is visible on the host side
> ("iscsiadm -m session -P3").
>
> So now, in the web GUI, there is no LUN showing up I could connect to.
> I have isolated the relevant logs - the engine one and the vdsm one :
>
> Engine : http://pastebin.com/32Sg85C8
> VDSM : http://pastebin.com/BbY6mVSk
>
> I don't know what is missing? May you help me?

I triple checked every parts I could check, but I don't know everything.
On the host that established the connection, I see that
iscsiadm -m session -P3
shows a correct connection, and shows /dev/sdb and sdc

But lvmdiskscan shows an error on sdb :
/dev/sdb: read failed after 0 of 4096 at 0...

multipath -ll
show nothing

/var/log/messages shows :
Oct 22 09:41:39 serv-vm-adms02 kernel: sd 13:0:0:0: [sdb] Test WP 
failed, assume Write Enabled
Oct 22 09:41:39 serv-vm-adms02 kernel: sd 13:0:0:0: [sdb] Asking for 
cache data failed
Oct 22 09:41:39 serv-vm-adms02 kernel: sd 13:0:0:0: [sdb] Assuming drive 
cache: write through
Oct 22 09:41:39 serv-vm-adms02 kernel: device-mapper: table: 253:3: 
multipath: error getting device
Oct 22 09:41:39 serv-vm-adms02 kernel: device-mapper: ioctl: error 
adding target to table

but I'm not sure multipath is to be involved at this point, so may not 
be relevant.

Beside debugging this, have you just some advices, some trails to follow?

-- 
Nicolas Ecarnot