[ovirt-users] oVIRT 4.1 / iSCSI Multipathing

[Uwe Laverenz]

Hi,


Am 17.07.2017 um 14:11 schrieb Devin Acosta:

> I am still troubleshooting the issue, I haven’t found any resolution to 
> my issue at this point yet. I need to figure out by this Friday 
> otherwise I need to look at Xen or another solution. iSCSI and oVIRT 
> seems problematic.

The configuration of iSCSI-Multipathing via OVirt didn't work for me 
either. IIRC the underlying problem in my case was that I use totally 
isolated networks for each path.

Workaround: to make round robin work you have to enable it by editing 
"/etc/multipath.conf". Just add the 3 lines for the round robin setting 
(see comment in the file) and additionally add the "# VDSM PRIVATE" 
comment to keep vdsmd from overwriting your settings.

My multipath.conf:


> # VDSM REVISION 1.3
> # VDSM PRIVATE
> 
> defaults {
>     polling_interval            5
>     no_path_retry               fail
>     user_friendly_names         no
>     flush_on_last_del           yes
>     fast_io_fail_tmo            5
>     dev_loss_tmo                30
>     max_fds                     4096
>     # 3 lines added manually for multipathing:
>     path_selector               "round-robin 0"
>     path_grouping_policy        multibus
>     failback                    immediate
> }
> 
> # Remove devices entries when overrides section is available.
> devices {
>     device {
>         # These settings overrides built-in devices settings. It does not apply
>         # to devices without built-in settings (these use the settings in the
>         # "defaults" section), or to devices defined in the "devices" section.
>         # Note: This is not available yet on Fedora 21. For more info see
>         # https://bugzilla.redhat.com/1253799
>         all_devs                yes
>         no_path_retry           fail
>     }
> }



To enable the settings:

   systemctl restart multipathd

See if it works:

   multipath -ll


HTH,
Uwe