How big are your VMFS datastores/how many VMs?

[jeberhardt42]

The suggestion for the 1:1 ratio was based on the assumption that they were far underneath the 256 LUN maximum for a VM host. This configuration is not impractical in the real world by any means, it only depends on the size of the VM environment that you manage and license/options that you have to manage that environment. If you don't have enterprise or enterprise plus licensing, you can't take advantage of SDRS where compiling multiple VMs in a single datastore makes sense.

[marktheblue45]

Fair point Joe.

                      Most environments I support are enterprise licence installations and have at least 100 VM's. Plus we use In-Guest iSCSI (and NCM) for SQL and Exchange so we'd soon run out of volumes on the array . As a general rule we have 10 SQL VM's per datastore and 15 max for general file and front end app servers. Only a guide and naturally one cap does not always fit all. The 1:1 ration mentioned give the same kind of advantages in terms of Snapshotting that In-Guest iSCSI does but with the advantage that VCentre isn't involved with the Quiescing process. I think the musc mooted VVols in VMware 6 will be a paradigm shift with a one to one relationship with the VM and it's VMDK as opposed o the datastre it resides on ......... If I've understood the web demos correctly. Matbe someone will enlighten me in this regard. Again it appears that Enterprise or even only Enterprise plus will have this feature and that's seems rather mean.

Regards,

              Mark.

[marktheblue45]

Excuse the Human to Keyboard errors in previous comments. Doh!

[marktheblue45]

SDRS
is only available with Enterprise Plus...... so annoying.

[Valdereth]

Looks like vSphere Standard and above! 

Compare VMware vSphere Editions and Kits Comparison | United States

[marktheblue45]

Hi Chuck,

               I have haven't seen more than 4 simultaneous snapshots. What happens is that 4 run and when one or more of the 4 finish others begin the snapshot process. If some VM's are busy and take a long time to quiesce it delays the whole process and exceeds the default Nimble timeout setting. I have use Nimble VMware integrated snapshots on Datastores with 20 VM's with no problem but they were "quiet" VM's. As a rule I have a max of 15 VM's per protected Volume collection.

Kind Regards,

                      Mark,