[PVE-User] Connect PVE Box to 2 iscsi server...

[Ronny Aasen]

On 16.08.2019 18:06, Gilberto Nunes wrote:
> Hi there
>
> Here I have two iscsi servers, that work together in order to provide
> a single connection for a certain initiator.
> Well at least to a Windows box when using MS iSCSI initiator.
> In such OS, I was able to connect using both iSCSI servers, and in
> Windows storage manager, I see just one HDD.
> So when I shutdown iscsi serverA, the HDD remain up and running, in Windows BOX.
> However, when I try to do that in PVE Box, I was enable to active
> multipath and I see both HDD from iSCSI servers, /dev/sdb and
> /dev/sdc.
> But I could not figure out how to make PVE see both HDD in storace.cfg
> in a single one storage, just like Windows box do!
> What do I missing??

Hello

I assume you need to use multipathd. I have something similar using 
Fiberchannel disks, but the method should be similar.

if it is not installed, you need to install  multipath-tools using apt.
check that multipathd is running.

run "multipath -v2" it should scan and create the multipath device.

with multipath -ll and dmsetup ls --tree  ; you should now see the multiple disks come together as a single device.

# example
# multipath -ll
3600000example00000292e42000b0000 dm-2 FUJITSU,ETERNUS_DXL
size=5.0T features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='0' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| |- 0:0:1:0 sdc 8:32 active ready running
| `- 2:0:1:0 sde 8:64 active ready running
`-+- policy='service-time 0' prio=10 status=enabled
   |- 0:0:0:0 sdb 8:16 active ready running
   `- 2:0:0:0 sdd 8:48 active ready running

verify you see the device under
/dev/mapper/3600000example00000292e42000b0000


use the device as you see fit. We use it as a shared lvm VG between multiple nodes for HA and failover.
But you can also format as your filesystem of choise and mount it as a directory, or run a cluster filesystem like ocfs or gfs and mount it as a shared directory.

good luck
Ronny