Having the ability to share raw disks via SCST (iscsi) on SCALE:
- defeats the purpose of our product since we're expecting the underlying filesystem to be ZFS but sharing raw disk allows the initator to write their own filesystem on top. Furthermore, unless the client writes a clustered filesystem on top of the rawk disk and another initiator accesses the iscsi target, then data corruption will occur.
- SCST clearly states (see here for more info) that if you share a raw disk and also access that disk using the sd,sg, or st driver which causes the drives state to change, that SCST will not be notified of it and can cause data corruption. Fenced, which is used in clustered and active/standby modes uses the sd or the sg driver for changing state of the disks.