I have figured it out.
After a reinstall from UI , I have managed to obtain the necessary change.
Here is what I have used:

hosted-engine --set-shared-config mnt_options 'backup-volfile-servers=gluster2:ovirt3' --type=he_shared
hosted-engine --set-shared-config mnt_options 'backup-volfile-servers=gluster2:ovirt3' --type=he_local
hosted-engine --set-shared-config storage 'gluster1:/engine' --type=he_local
hosted-engine --set-shared-config storage 'gluster1:/engine' --type=he_shared

And the result after reinstall with deploy is as expected:

# grep -E 'storage|mnt_options' /etc/ovirt-hosted-engine/hosted-engine.conf
storage=gluster1:/engine
mnt_options=backup-volfile-servers=gluster2:ovirt3




В събота, 12 октомври 2019 г., 15:33:15 ч. Гринуич+3, Strahil <hunter86_bg@yahoo.com> написа:


Hello All,
Recently I wanted to enable nested virtualization on my cluster  and thus I had  to redeploy the first host.

Sadly, some time ago I have taken the shortcut  and changed  the values in
/etc/ovirt-hosted-engine/hosted-engine.conf locally in order  to replace  the gluster host and mount options.

Thus, after the redeploy, I had to restore  the old config in order to be able to mount the shared storage.

Now I want to make the proper changes and according to an old thread I need to run the following commands , but they fail.
Can some one advise what is the correct syntax ?

[root@ovirt1 ~]#  hosted-engine --set-shared-config storage gluster1:/engine
Duplicate key storage, please specify the key type. Available types are: ['he_local', 'he_shared']

[root@ovirt1 ~]# hosted-engine --set-shared-config mnt_options backup-volfile-servers=gluster2:ovirt3
Duplicate key mnt_options, please specify the key type. Available types are: ['he_local', 'he_shared']

Best  Regards,
Strahil  Nikolov

Hello All,
Recently I wanted to enable nested virtualization on my cluster  and thus I had  to redeploy the first host.

Sadly, some time ago I have taken the shortcut  and changed  the values in
/etc/ovirt-hosted-engine/hosted-engine.conf locally in order  to replace  the gluster host and mount options.

Thus, after the redeploy, I had to restore  the old config in order to be able to mount the shared storage.

Now I want to make the proper changes and according to an old thread I need to run the following commands , but they fail.
Can some one advise what is the correct syntax ?

[root@ovirt1 ~]#  hosted-engine --set-shared-config storage gluster1:/engine
Duplicate key storage, please specify the key type. Available types are: ['he_local', 'he_shared']

[root@ovirt1 ~]# hosted-engine --set-shared-config mnt_options backup-volfile-servers=gluster2:ovirt3
Duplicate key mnt_options, please specify the key type. Available types are: ['he_local', 'he_shared']

Best  Regards,
Strahil  Nikolov