Ceph

From https://pad.ceph.com/p/Report_Documentation_Bugs:

"Applications that use SCSI 7 perstistent group reservations (PGR) and SCSI 2 based reservations are not supported when exporting a RBD image through more than one iSCSI gateway.
Misleading: the current ceph iscsi gateway does not support reservations in any scenario. The tcmu-runner approach lacks any code to handle this.
In addition, the iscsi code is in maintenance and potential users should be alerted to the overall development status of ceph iscsi.
https://docs.ceph.com/en/latest/rbd/iscsi-initiators/