I'm facing storage system that while generally advertising support for WRITE_SAME_16 with UNMAP in reality fails this request depending on exact volume configuration. This configuration is done on storage side and may happen after host initially discovered LUN. I though about simply overriding kernel auto-detect with UNMAP using sysfs scsi_disk/.../provisioning_mode attribute, but it appears kernel may re-evaluate it in some cases, so changes do not stick. Is it possible to permanently restrict it per-device (or per-vendor/device)? TIA -andrei
