Still seems the idea is good. Here is the example of lrbd configuration file, which allows to serve single iSCSI target with 4-way multipathing to 4 OSD nodes.
{
"auth": [
{ "target": "iqn.2016-07.org.ses-iscsi.igw.x86:mpath", "authentication": "none" }
],
"targets": [
{
"target": "iqn.2016-07.org.ses-iscsi.igw.x86:mpath",
"hosts": [
{ "host": "osd01", "portal": "portal01" },
{ "host": "osd02", "portal": "portal02" },
{ "host": "osd03", "portal": "portal03" },
{ "host": "osd04", "portal": "portal04" }
]
}
],
"portals": [
{ "name": "portal01", "addresses": [ "172.18.65.144" ] },
{ "name": "portal02", "addresses": [ "172.18.65.153" ] },
{ "name": "portal03", "addresses": [ "172.18.65.154" ] },
{ "name": "portal04", "addresses": [ "172.18.65.155" ] }
],
"pools": [
{
"pool": "iscsi01",
"gateways": [
{
"target": "iqn.2016-07.org.ses-iscsi.igw.x86:mpath",
"tpg": [ { "image": "iscsivol01" } ]
}
]
}
]
}