Generally we never give thought about VCMDB database once we initialize first time. It does make sense when you messup or did some thing disaster. This database is most impppppportaaaaaaant for DMX. Once you loose this database means you can't get DMX configuration back at any cost. So, I am discussing different type of VCMDB on DMX.
We can now support up to 16,000/64000 addressable devices enginuity 5771 onward and therefore the Volume Control Manager Database needs to be physically larger. At 5670, as per EMC recommend CE's were encouraged to create 96 cylinder (minimum) VCMDB during new installs. This was to cater for future upgrades to 5671.
To summarize the VCMDB type applicable to DMX :
• Type 3 - this can cater for 32 fibre or iSCSI initiators per port. Introduced with Enginuity 5669 and requires a 24 cylinder (minimum) VCMDB and Solutions Enabler v5.2.
• Type 4 - this can cater for 64 fibre or 128 iSCSI initiators per port. Introduced with Enginuity 5670 and requires a 48 cylinder (minimum) VCMDB and Solutions Enabler v5.3.
• Type 5 - this can support 64 fibre or 128 iSCSI initiators per port AND cater for 16,000 devices. Introduced with Enginuity 5671 and requires a 96 cylinder (minimum) VCMDB and Solutions Enabler v6.0. (Note: without a type 5 96cyl VCMDB and SE 6.0 you will be restricted to 8192 logical volumes as in 5670).
• Type 6 - this can support 128 fibre or 256 iSCSI initiators per port AND cater for 32,000 devices available on DMX-3 with Enginuity 5771 (at GA release). Currently the Type 6 database (at latest Enginuity 5771 with Solution Enabler 6.0 and above) will cater for 256 fibre or 512 iSCSI initiators and 64,000 logical devices.
What is requirement for Type 5:
The three requirements for a Type 5 VCM database on DMX (and support for up to 16,000 customer addressable volumes) is a correctly configured 96 cylinder VCMDB device, Enginuity 5671 and Solutions Enabler v6.0 or above. Note that the VCMBD “type” reflects the internal data structure of the Volume Control Manager Database. Therefore a 96 cylinder VCMDB size does NOT mean that you have a Type 5 VCMDB.
• At 5670 with a 48 cylinder VCMDB it is still type 4.
• At 5670 with a 96 cylinder VCMDB it is still type 4.
• At 5670 with a 96 cylinder VCMDB and SE 6.0 it is still type 4 - do not try to convert the database using the SYMCLI (EMC do not support more than 8192 logical volumes at 5670).
• At 5671 with a 48 cylinder VCMDB and SE 6.0 it is still type 4 - the VCMDB is NOT physically large enough.
• At 5671 with a 96 cylinder VCMDB and SE 5.5 it is still type 4 - the VCMDB is large enough but SE 5.5 does not support the Type 5 database.
• At 5671 with a 96 cylinder VCMDB and SE 6.0 it is a type 5 database - if you have run the “symmaskdb convert -vcm_type 5” command. Be aware that if you convert from a lower type database to a higher type, any hosts running a Solutions Enabler version that does not support the higher VCMDB type will NOT be able to access the "new" database.
• At 5771 (DMX-3) the VCMDB data now resides in the SFS volumes. At 5771 the VCMDB should be configured the SAME size as a standard FBA gatekeeper (this can be 3 cylinders due to the 64KB track size but 6 cylinder, as recommended in some guides, is also perfectly acceptable) but it must still be assigned the VCM fibre gatekeeper status. Note that the VCMDB "gatekeeper" on DMX-3 is no longer shown as "write disabled" (it is now a "gatekeeper" rather than a physical volume used for physical storage - the Volume Control Manager data is protected and stored on the internal SFS volumes).
• Note that Enginuity 5771 will ONLY support a Type 6 VCM database (again the data is resident on the SFS volumes). This re-location of the physical database to the SFS volumes caters for the increased host connectivity AND the increase in logical volumes supported with DMX-3.