My first experience of Symmetrix and VMware host connectivity and provisioning was back in the days of ESX 3.0.0 and DMX-3s running 5771 code and things have changed since then.
On the ESX side no more manual VMFS partition alignment and numerous other changes enabled by the vStorage APIs that are a great show of maturity and integration on both the VMware and storage vendor fronts. On the Symmetrix side we now have VP, FAST-DP, FAST-VP, Virtual LUN, Auto-Provisioning and other significant integration improvements made available via the excellent EMC Virtual Storage Integrator (VSI) plug-ins for vSphere.
What hasn't really changed that much (if you've been through the SPC-2 enablement with ESX 3.x) is the bit settings on the FA ports and with the release of vSphere 4.1 a few months back I revisited the Fibre Channel SAN Configuration Guide that notes the bit settings (or flags) that are required on Symmetrix.
If you are lucky enough to have VMAX and not DMX then the change you'll love is that device masking or 'fibrepath enabled' has changed to Auto-Provisioning groups. Administrators of large clusters will love this feature as it will save so much time when presenting out new devices or introducing new nodes into the cluster.
My notes on the bit settings are below.
Notes on Symmetrix bit settings for vSphere
NOTE
Always check the EMC E-lab Navigator or EMC Support Matrix for up to date support info.
Requirement copied verbatim from the vSphere 4.1 Fibre Channel SAN Configuration Guide
EMC Symmetrix storage systems work with ESX/ESXi hosts in FC SAN configurations. Generally, you use the EMC software to perform configurations. The following settings are required on the Symmetrix networked storage system. For more information, see the EMC documentation.
The ESX/ESXi host considers any LUNs from a Symmetrix storage array with a capacity of 50MB or less as management LUNs. These LUNs are also known as pseudo or gatekeeper LUNs. These LUNs appear in the EMC Symmetrix Management Interface and should not be used to hold data.
- Common serial number (C)
- Auto negotiation (EAN) enabled
- Fibrepath enabled on this port (VCM)
- SCSI 3 (SC3) set enabled
- Unique world wide name (UWN)
- SPC-2 (Decal) (SPC2) SPC-2 flag is required
The settings in the bullet points are FA port flags and are split into two categories - SCSI port flags and Fibre port flags.
Currently the VMware vSphere 4.1 Fibre Channel SAN Configuration Guide does not note that the ACLX flag is required to enable Auto-Provisioning groups on VMAX nor does not note that the OS2007 bit is optional.
SCSI port flags
Common_Serial_Number [C] enabled
- Provides a unique serial number on multiple paths for the same Symmetrix device.
- Needs to be enabled if multipathing is being used.
- Alters the INQUIRY data to to report that any device on the port supports ANSI version 'SCSI-3 SPC' (0x3).
- For WSFC guests the SCSI-3 persistent reservation (or [PER] bit) must still be set on the devices it uses that are under cluster control.
- Required to make use of SPC2.
- Alters the ID of the LUN to contain the network address authority (NAA) identifier.
- The LUN serial number is stored on page 0x80 and the NAA ID is stored on page 0x83.
- ESX/ESXi 3.x and higher read the INQUIRY data from page 0x83 (NAA id) as opposed to 0x80 (LUN serial number).
- In ESX/ESXi, the NAA ID is persistent through reboots whereas the runtime name of the device is not.
- Required for advanced SAN-aware applications such as VMware Site Recovery Manager and the EMC Virtual Storage Integrator suite.
- From the VMware documentation: "When enabled, this flag provides stricter compliance with SCSI standards for managing device identifiers, multiport targets, unit attention reports, and the absence of a device at LUN 0."
Fibre Protocol port flags
ACLX or Fibre path enabled on this port [ACLX] enabled (VMAX 5874 and higher only)
- Enables Auto-Provisioning Groups on the port.
- Enabled for device masking or volume logix.
- Enables a handshake between two ports for optimal data transfer.
- Ensures unique World Wide Names in the fibre environment for the array components by using the Symmetrix serial number and port numbers.
References
- Solutions Enabler Documentation Set (Powerlink account required)
- vSphere 4.1 Fibre Channel SAN Configuration Guide
