Does ASAr2 support NVMe/FC persistent port ?

[Chun_Chiang]

My question is 

Does NVMe/FC persistent port support include ASAr2 or just only ASA ?

I am not sure what ASA means. Does it also include ASAr2 ?

From TR-4080,

ONTAP Overew, Takeover and giveback :

Should a controller fail, its partner assumes data service provision using its own interfaces. if the node is an ASA, then persistent ports and/or iSCSI LIF failover are enabled and supported, failed interfaces are reactivated on the partner by either migrating the IP address (iSCSI LIF failover) or relocating the HBA WWNN (for FCP and NVMe/FC persistent ports), ensuring hosts do not encounter lost storage paths.

Thanks and regards,

Chun Chiang

[chamfer]

Hi @Chun_Chiang ,

A great question, I have some thoughts, but I am not sure if I have the right answer for, but I can answer your other questions:

• ASA (All SAN Array) is the NetApp Block only version of ONTAP which is different from the AFF (All-Flash FAS)...... yes marketing is confusing.... the AFF supports file, block, and object.
• ASAr2 is just newer hardware than ASA and "generally" support for features is ONTAP version and platform (ASA/AFF) specific.

Now to answer your question, I don't believe that NVMe/FC persistent port is a feature due to the following:

1. This links advises that FC is required for Persistent port All-Flash SAN Array configuration limits and support
2. This document "Implementing and Configuring Modern SANs with NVMe/FC | TR-4684 | NetApp" states
   1. The ONTAP implementation of NVMe/FC requires application-level high availability. If a controller loss or path failure occurs, the application host must manage path failover to its (application) HA partner. This limitation exists because the NVMe multipathing specification called ANA, analogous to ALUA in SCSI protocol, was still under development.
      While implementing NVMe/FC, NetApp helped design the ANA protocol in the NVMe forum,
      where it was recently ratified. A future release of ONTAP will offer support for this enhancement.; and
   2. Although ONTAP uses a NVMe/FC LIF that is separate from the FCP LIFs, both LIFs can be hosted on the same physical HBA port at both the host initiator and storage target. NVMe/FC and FCP can share the same physical infrastructure concurrently, so the same physical port, cable, switch port, and target port can simultaneously host and transmit both FCP and NVMe/FC frames. The two protocols are separated at the logical rather than physical layers, making adoption and transition from FCP to NVMe/FC simple and seamless.
3. KB documentation "How to enable or disable SAN FCP Persistent ports feature on DATA ONTAP 9.8 ASA platform".  I know its old (2020), but it has not been updated which may be a sign that it is still current.

I hope that this helps, it would be great to get some input from NetApp.

Enjoy!

[Chun_Chiang]

Thanks for your reply.

I used LOD new ASA 9.16.1 to do the test.

In diag mode, san config show

display 

Persistent Port Enabled : True

I created total 2 FCP LIFs and 2 NVMe/FC LIFs. 

All LIF is located at home node.

All LIFs failover policy are all disabled.

Even I follow KB

https://kb.netapp.com/on-prem/ontap/da/SAN/SAN-KBs/How_to_enable_or_disable_SAN_FCP_Persistent_ports_feature_on_DATA_ONTAP_9.8_ASA_platform

to disable one FCP LIF, I didn/tobserve any difference.

It seems persistent port shadow LIF are hidden and can'r be found by CLI.

But it seems that ASAr2 still have persistent port feature with FCP and NVMe/FC just like old ASA.

If we can get confirmation from NetApp. that will be great.

[Chun_Chiang]

I used LOD ASAr2  9.16.1 to verify by CLI. I found 

FCP and NVMe/FC LIF failover policy are all disabled. I can’t change them to sfo-partner-only.

so there is no persistent port on ASAr2. All block protocols use symmetric multipath.

[Chun_Chiang]

I use san config shown (in diagram mode)

and get Persistent Ports Enabled: true

What failover-policy of old ASA system which supports persistent port feature with FCP and NVMe/FC use ? disabled or sfo-partner-only ?

if it is disabled. Does it mean ASAr2 still have persistent port feature on FCP and NVMe/FC use ?

[Chun_Chiang]

If persistent port will have two same WWPN : one is -is-home, the other is not -in-home, then what I see in ASAr2 is single WWPN LIF. So it should be no persistent point for FCP and NVMe/FC.

[Chun_Chiang]

On LOD new ASA  9.16.1 In debug mode, san config show

display

Persistent Ports Enabled : True

Does it mean FCP and NVMe/F C persistent port is enabled by default ?

[jaikumar]

In Short PPorts is Internal Engineering Team , while it is SCSI FC LIF Failover. And in all Platforms FAS/ASAr1/ASAr2 we dont support NVMe FC LIF Failover.

LIF Failover : LIFs failover to the HA Partner (same ports) in event of Storage Failover Over (takeover). And Failback to orginal Ports after giveback.

--

LIF Type	FAS	AFF	ASAr1	ASAr2
SCSI FC LIF	NOT Supported	NOT Supported	Supported	Supported
NVMe FC LIF	NOT Supported	NOT Supported	NOT Supported	NOT Supported
iSCSI LIF	NOT Supported	NOT Supported	Supported	Supported
NVMe TCP LIF	NOT Supported	NOT Supported	NOT Supported	NOT Supported

Note: 

In ASA r1, iSCSI LIFs use the default-data-iscsi service policy, and NVMe/TCP LIFs use default-data-nvme-tcp. In ASA r2, all IP LIFs (for both iSCSI and NVMe/TCP) use a single service policy called default-data-blocks.

Failover behavior:

* LIFs with default-data-iscsi can fail over. LIFs with default-data-blocks or default-data-nvme-tcp cannot fail over.

[Chun_Chiang]

Thank you for detail explanation. 

So NVMe/FC will not have PPorts on ASA and ASAr2.
Tr-4080 page 10,

"if the node is an ASA, then persistent ports and/or iSCSI LIF failover are enabled and supported, failed interfaces are reactivated on the partner by either migrating the IP address (iSCSI LIF failover) or relocating the HBA WWNN (for FCP and NVMe/FC persistent ports), ensuring hosts do not encounter lost storage paths."

It should be corrected to "(for FCP persistent ports)"

Can we conclude ASA and ASAr2 persistent port only support FCP ?

[jaikumar · Accepted solution]

Yes @Chun_Chiang. Let me propose the change in the TR , so that it clearly states FC LIF Failover in ASA only supports SCSI and NOT NVMe.