hesela.devSAS zoning
SAS zoning controls which groups of expander PHYs may communicate by applying configured access permissions.
In PHY-resolved zoning, expander PHYs belong to zone groups whose permission table controls communication. Hosts sharing a SAS domain need not have access to the same storage. [2]
Zoning, table-to-table routing and self-configuration are separate capabilities. Reachability alone does not establish access policy, encryption or independent failure paths. [1] [2]
The smp_discover documentation explains that zoning-hidden PHYs can appear as 'phy vacant'; --ignore sets the request's Ignore Zone Group bit. A broader management view is not an access grant for ordinary I/O. Record initiator identity and request options when comparing inventories. [3]
A 2008 domain-management proposal distinguishes ordinary I/O, zone management and domain management. These roles can differ even for the same initiator. [4]
In the storage-module configuration documented by the cited service manual, moving the module to a different chassis slot erases saved expander zoning assignments. That maintenance constraint is product-specific: follow the enclosure's recovery procedure before diagnosing a failed drive. Do not disable zoning as a generic discovery fix. [2]
Relations
- related
- Serial Attached SCSI (SAS), SAS expander, SAS physical PHY, Serial Management Protocol, SCSI initiator and target, Dual-port drive
Advantages
- Can assign storage access to selected hosts within a shared SAS fabric. [2]
Limitations
- The expander, management software and active configuration must support and enforce the intended policy. [1]
- Access separation does not remove shared hardware failure domains. [2]
Citations
- Microchip SXP 12 Gbps SAS Expander Family, DS00003036A (July 2019), pp. 1-2: table-to-table routing, zoning and address support
- Oracle Sun Blade Storage Module M2 Service Manual (January 2012), pp. 9-10 and 12: zoning, access permissions and dual paths
- Oracle Solaris smp_discover(8), July 2022: --ignore and zoning-hidden PHYs
- Brad Besmer, T10/08-267r1 file: SAS-2 Domain Management Zoning Interaction, 14 July 2008, Overview p. 1
Sources & caveats
- The implementation examples are Oracle Sun Blade Storage Module M2 and Microchip SXP 12G. No universal zone-count limit, current product survey or penetration test is claimed.
- Encryption and redundancy distinctions are engineering consequences of connection-permission control, not measured guarantees.
- SAS access zoning is distinct from zoned block storage, where zones describe media address ranges and write rules.
- The T10 URL ends in 08-267r1.pdf but its internal header says Revision 0; the cited overview is dated 14 July 2008. No experiment on a SAS fabric or access-control bypass was performed.
- The slot-relocation constraint applies to Oracle Sun Blade Storage Module M2, January 2012 manual pp. 18-19; it is not a universal behavior of SAS shelves.