7 Replies Latest reply: Jun 12, 2014 10:03 AM by Stephen Newhauser RSS

    How do I replicate in guest iSCSI disks offsite without TWO Nimbles?

    Ian Steele Newbie
    Visibility: Open to anyone

      So we recently purchased a C260G Nimble array. We love it.  Ive been migrating my data from our RDM Fibre Channel LUNS (old SAN) onto in guest attached iSCSI Nimble LUNS.  VSS and snapshots are working great.  Ive come to a problem however.  I just realized that now my disks are no longer exposed to vmware.  I was using VMware replication (VR) found in 5.1 to replicate my VMs offsite.  Now I cannot use this and honestly am a little scared because I can't find a product available that will replicate the disks for me (in guest iSCSI).  What do you suggest I do in this situation.  I know Nimble would say "well buy another array and then just choose replicate".  Well we can't do this right now.  I also know the Nimble team is working with VEAM on a product that will manage and replicate snaps to a any kind of storage using VEAM.  We have another type array at the DR site and I am desperately trying to find a solution to replicate these in guests iSCSI disks offsite.

       

       

      Any suggestions would be greatly appreciat

        • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?
          Roland Browne Wayfarer

          Hi Ian,

           

          You have a few options here - but not all of them may be viable to you:

           

          Option 1. Replicate using another Nimble array

          Pros

          • This is by far the easiest replication option for you since it doesn't require any changes to the layout of your storage environment.
          • No software licenses required
          • VMware SRM integration

          Cons

          • You need to another Nimble array

           

          Option 2. Replicate using host based software eg. Double-Take / Neverfail / Veeam

          Pros.

          • Relatively easy to implement & configure
          • Doesn't require any changes to your current storage layout
          • Can be cost effective in a small environment

          Cons

          • Each host requires a software license (can be expensive in a large environment)
          • Each host is managed individually (can limit practical scalability)
          • Limited / No VMware SRM integration
          • Depending on the product it may not protect the entire VM (just the data volumes)
          • Limited OS support

           

          Option 3. Use vSphere replication (again)

          Pros

          • VMware SRM integration
          • Replication managed from within VMware (single pane of glass)

          Cons

          • Disks must be VMDKs or vRDMs (you would need to convert your existing iSCSI guest LUNs)

           

          If getting another Nimble array is not an option for you right now I'd say that going back to using vSphere replication is probably your best bet. It will just mean that you will need to convert the iSCSI guest LUNs into vRDMs.

           

          Hope that's helpful. Keep us posted on your progress

           

          Rols

            • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?

              Thanks so much for that reply.  Two follow up questions.

               

              I already have a product from a company called Inmage which is a CDP based replication technology that uses agents on each VM.  In order to replicate as application consistent it would have to make its own VSS calls to the OS.  Can I have two apps (Nimble and Inmage) making VSS calls to the same disk?

               

              Option 3 seems like what I will most likely do.  When I switch to iSCSI RDM and use VMware for snapshots instead of NCM how does that affect my volume collection protections?  Is the VMware snap technology as good as the Nimble one?  Do the snaps still gets stored on the Nimble array or do they get stored somewhere in vCenter?

               

              Thanks again

                • Re: Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?
                  Roland Browne Wayfarer

                  I already have a product from a company called Inmage which is a CDP based replication technology that uses agents on each VM.  In order to replicate as application consistent it would have to make its own VSS calls to the OS.  Can I have two apps (Nimble and Inmage) making VSS calls to the same disk?

                  Yes it is possible to have 2 different applications making VSS calls to the same disk / application - you will want make sure they have different schedules so they don't attempt to call at the same time.

                   

                  When I switch to iSCSI RDM and use VMware for snapshots instead of NCM how does that affect my volume collection protections?  Is the VMware snap technology as good as the Nimble one?  Do the snaps still gets stored on the Nimble array or do they get stored somewhere in vCenter?

                  Unfortunately when you move the iSCSI LUNs to vRDMs NPM will lose visibility to the Nimble LUNs (sorry I should have listed that as a con). Which means that the Nimble array will lose the ability to take VSS consistent snaps. You can take still take Nimble snaps but they will only be crash consistent. The VMware snapshots (used for replication) will be entirely controlled and stored by VMware. VMware snaps are not as efficient and can impact system performance unlike the Nimble Snaps however for short term protection and replication use they can be effective.

                   

                  Here is a 4th option.....

                   

                  Option 4 - Move all data to VMDKs

                  Pros

                  • Enable you to have Nimble VM consistent snapshots (via vCenter Plugin)
                  • Support for vSphere replication

                  Cons

                  • Lose ability to snap on a per VM / Guest LUN basis (since snapshots will be at the datastore level)
                  • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?
                    rfenton Tracker

                    Just a note - if your using some form of Appliance/Application based replication it will be well worth checking what granularity the changed blocks are replicated.  I've seen a couple of solutions that use quite large page sizes when it comes to replication which ultimately means subsequent reads on the Nimble Storage array and therefore results in additional read activity.   This can manifest itself in higher cache utilisation then had you been using array based replication.

                • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?

                  Yes my solution is application/appliance based.. i see that it might ***** up the caching. 

                   

                  One question regarding Option 4 - moving data to VMDK.  In this scenerio i instruct Nimble to use vcenter for VSS calls.  When vcenter makes a call do I see it in the windows event logs like I do with the native nimble snaps?  Are they otherwise the same to nimble as snapping a in guest iSCSI LUN.

                   

                  My fear of moving to vmdk is losing the performance policies like SQL, SQL LOGS, Exchage DB and that sort.  I would have to have VMFS for all my LUNS and that seems excessive.  Im waiting to hear back from those using purely VMDK to see how their performance is vs in guest iSCSI and what their DR plan looks like.

                   

                  <------------------wishing that Veeam would hurry up their integration with Nimble so I can just use them to replicate the snaps to another type storage device.

                    • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?
                      rfenton Tracker

                      With the Native Nimble volumes we are communicating with our VSS provider.  When using VMWare we are using the sync IO drivers within vSphere.  I'd need to double check but I think you will see some form of message in the Event Log but it will be a VMWare related one and not Nimble (as the guest is completely unaware that it's storage is on a Nimble platform).

                       

                      As for Performance Policies - they can largely remain the same as long as all the data on the datastore is performing a similar task. There is a thread here that covers a similar topic:

                      https://connect.nimblestorage.com/message/1536#1536

                       

                      In this scenario it makes sense to provision datastores related to Service level.  So a Data datastore will have SQL-Data as it's performance policy and a Logs Datastore will have SQL-Logs as it's performance policy.  As Wen states in the blog referenced it the fact they are VMFS volumes shouldn't impact the Application profile that we are seeing.  I like this approach as essentially you think about volumes in terms of what services will run on them and what attributes you wish to apply to them (Cached, Compressed, Replicated, Not replicated etc etc)

                       

                      Hope this helps

                      • Re: How do I replicate in guest iSCSI disks offsite without TWO Nimbles?
                        Stephen Newhauser Newbie

                        Ian-

                         

                        Virtacore has a Nimble to Nimble replication service offering. We've are Nimble largest and longest service provider.  We have a VMware, Cisco UCS and Nimble stack hosted in our Equinix Tier 3 data centers.

                         

                        Our Nimble offering is structured as Storage (per GB per month) and a standby VMware resource pool that completely mirrors your production VMware environment (for $199/ month).

                         

                        If you failover then there would be an additional charge for compute but we provide a cost estimate up front and everyone we've talked with thinks its a great value ie we're not going to take advantage of you while you in trouble.

                         

                        This service comes with 2 annual tests and joint run book development (no finger pointing).

                         

                        This offering is really starting to gain traction and its a extremely affordable way for midmarket or regional companies to have a completely mirror geo-diverse data center.

                         

                        Joe Diller is the rep in your area.

                        jdiller@virtracore.com

                        703.246.1440

                        We'd love the opportunity to see if we can earn your business.

                         

                        Thanks

                        Stephen