VizioncoreDatacore Whitepaper

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Page 1DataCore Software Corporation

6300 N.W. 5th WayFort Lauderdale, FL 33309www.datacore.com

DATACORE SAN COOKBOOK #12

VCDC

A Cost-Effective DR and Offsite Backup Solution Using Vizioncore’s vRanger Pro™ and DataCore’s SANmelodywith Asynchronous Replication

November 19, 2007

Version 1.0

Authored by:

Tim Warden Joseph Ahn

DataCore Software Corporation Vizioncore, Inc.(520) 260-8119 [email protected] [email protected]





EXECUTIVE SUMMARY

Over the course of the last few years, implementing a Disaster

Recovery project has become a priority for most businesses,regardless of their size. It is now commonly accepted that although

the SMB may not have the same IT budget as large enterprises, theytypically have the same imperatives in terms of data protection andavailability. Countless studies conducted and articles published all

conclude that businesses without a proven DR strategy usually do notsurvive a datacenter disaster.

With the advent of server virtualization, many smaller businesses havebegun to rethink the feasibility of implementing a DR solution.

However, they soon realize that server virtualization alone is not

enough. An infrastructure must be put in place to replicate the data tothe DR site and make it available for rapidly redeploying theapplications.

Many of the hardware and software vendors offer products that can

serve as tools to create the infrastructure, but the solutions vary interms of complexity, completeness, and reliability.

In this white paper we present a complete solution for implementingan offsite backup that doubles as a DR solution that can be rapidly

turned on. The solution combines two Best of Breed products.Vizioncore’s vRanger Pro will be used for backing up virtual machines

and their data at the primary datacenter. SANmelody from DataCoreSoftware Corporation will be used as a SAN Storage Array, offeringAsynchronous Replication to mirror the backups to the DR site.

The objective is to architect a solution that is elegant, automated,reliable, and cost-effective.





TOPICS DISCUSSED IN THIS WHITE PAPER

Asynchronous Replication Defined

Solution Overview

Creating a SANmelody Virtual Volume for vRanger Pro

Establishing the Asynch Mirror to the DR SANmelody Server

Taking the Backups

Automating the Backup Process

Using the Replicated Backups

Restoring a Replicated VM

Offsite Backups

ASYNCHRONOUS MIRRORING DEFINED

Asynchronous Mirroring or Asynchronous Replication is a means of

copying data from one server or storage array to another. The twosystems are typically separated across different geographies and thus

the distance and available network bandwidth between the two sites

introduce latency that precludes the use of Synchronous Mirroring.

Thus the servers use a “store and forward” mechanism, buffering thedata locally until it can be sent across what is often a slow (e.g. DS3)link.

DataCore Software Corporation implements this feature in the AIM

(“Asynchronous IP Mirroring”) option for their SANmelody andSANsymphony products.

For an in-depth review of Asynchronous Replication and DR, pleaserefer to the DataCore white paper on “DR and AsynchronousReplication”.





SOLUTION OVERVIEW

In this white paper we will be using VMWare ESX servers for our

Server Virtualization environment, both at the datacenter in Tucson,Arizona and at the DR site in Austin, Texas.

The Vizioncore vRanger Pro product will take backups of the VMs on

the ESX hosts in the datacenter.

DataCore’s SANmelody product will be used to implement a SANStorage Array, providing shared storage to any of the ESX hosts and

enabling VMotion. We will provision a virtual volume for use byvRanger as a destination for the backups. SANmelody’s AIM or

“Asynchronous IP Mirroring” option will be used to replicate thevRanger backups to a SANmelody server at the DR site.

Network Diagram of Solution

The replicated vRanger Pro backup volume can serve as an offsite backup,

or we can choose to use that datastore to implement a traditionalbackup according to our backup policy. We can even use SANmelody’s

Snapshot option to implement disk-to-disk backups, if required.

Finally, we will test our solution, restoring VMs from the replicated

volume to our DR site’s ESX server.





CREATING THE SAN VOLUMES

SANmelody is a software package that implements a SAN StorageArray with native Fibre Channel and iSCSI support. SANmelody runs

on a standard Windows x86 platform and can “virtualize” any storagepresented to the Windows LDM (Logical Disk Manager).

Commodity SAS or SATA drives can be pooled, from which virtualvolumes (or LUNs) are taken and presented over iSCSI or FibreChannel to the storage clients – our ESX hosts, SQL, Exchange and

File servers, etc.

SANmelody Virtual SAN Storage is ideal for ESX Servers

The SANmelody GUI is an intuitive and easy-to-use set of snap-ins inthe Windows Management Console. If you can manage a Windowsserver, you can manage SANmelody.

In the dialog below, a new Thin Provisioned virtual volume named “vRanger” is mapped to our VirtualCenter server which hosts vRanger

Pro.





Screenshot of Volume Mapping

SANmelody implements the complete SCSI3 recommendation and is

ideally suited to any SAN storage application, including its use forcreating VMotion-enabled VMFS volumes for VMWare HA or DRS.Here, our “vRanger” volume will be used for saving vRanger Pro

backups.

ESTABLISHING AN ASYNC MIRROR

Asynchronous IP Mirroring (AIM) is an optional licensed feature of

SANmelody. It allows two cooperative SANmelody Storage Arrays toreplicate SAN volumes over standard IP.

At our DR facility, we install a second SANmelody Storage Array,creating virtual volumes that will receive the replication from the

SANmelody server at our datacenter. In this example, we create asingle virtual volume which will receive the replication of our “vRanger”

volume. We name the virtual volume “AD-vRanger”, an arbitraryprefix to remind us that the volume is an active AIM Destinationvolume. We then add it to the AIM Destination Manager’s list of

replication volumes, as shown in the following screenshot.





AIM Destination Virtual Volume

At the source site, we establish an AIM relationship between the two

SANmelody servers, creating a new “Destination Node”. We specifythe name and IP address or our SANmelody server at the DR site.

Specifying the AIM Destination Node

We then create the AIM relationship between our source “vRanger” virtual volume and the replication target, our “AD-vRanger” virtual

volume.





Creating The AIM Volume Relationships

Useful Tip: Normally at this point, we would need to “initialize”

our mirror to bring the source and destination into synch.However, in this case, we have not yet formatted the source

“vRanger” volume on the vRanger Pro server, so in effect thetwo volumes are in an unknown state. Formatting the volume

(e.g. creating an NTFS file system) will result in the NTFS catalog

being replicated to the DR site, effectively synching the twovolumes.

We are now actively replicating our vRanger backup volume to the DR

site.





CREATING THE vRANGER VOLUME

Thus far we have mapped a LUN from SANmelody to our vRanger Pro server and are actively replicating to the DR site. After a “Rescan

Disks” in the Windows LDM, we discover our SANmelody volume,format it and mount it.

The Disk Properties Dialog of a SANmelody Disk

Just for the sake of clarity and organization, we create a folder called

“vRanger” on the volume. This folder will be used to hold our backups.





TAKING THE BACKUPS

We install Vizioncore’s vRanger Pro product on our Virtual Centerserver and use it to backup our VMs for replication to the DR site.

vRanger Pro features an intuitive, easy-to-use GUI, complemented by aCLI interface.

Launching the GUI, we click the “Backup VM(s)” button to prepare ourbackups. The Backup interface involves three screens titled “Source”, “Destination” and “Options”.

In the “Source” screen, we select those VMs and/or their disks that wewish to backup. For instance, we could decide to backup the relatively

static “C:” drive .vmdk files for the VMs once every 2 weeks, and

backup their “D:” data drive .vmdk files nightly.

Selecting VM’s to Backup





After selecting the VMs targeted for backup, we navigate to the “Destination” tab to select the volume on which we want the archives

to be placed – in this case, the “vRanger” folder we created on ourSANmelody vRanger Pro volume.

Selecting the vRanger Destination Datastore

vRanger Pro can backup the VMs to VMFS volumes, or to NFS or CIFS(i.e. SMB or Windows) shares. Backing up to a VMFS volume

eliminates LAN traffic as it is a block level operation using the SAN.vRanger Pro also integrates with VCB (VMware’s Consolidated Backup

framework). Using vRanger Pro with VCB will yield even faster LAN-freebackups.

Nonetheless, most vRanger Pro customers prefer using Windows shares asit permits taking differential backups. It also offers performance

advantages over backing up to a console-based VFMS datastore.





Clicking the Options tab, we can control aspects of the backups. Forinstance, we can choose to automate full vs. differential backups.

Taking differentials will radically improve the utilization of our inter-site bandwidth.

In the screenshot below, this vRanger Pro backup job will take a full

backup every 14 days, and take differentials in between.

Selecting vRanger Backup Options

Notice the “Encrypt Data Transfer” flag. We may use this feature tosecure our data against hackers when, for example, we are backing up

over an unsecured link. We’ll talk more about this when we discussoffsite backups.

vRanger Pro can also install and enable VSS agents in Windows VMs. VSSwill provide application “quiescing” prior to taking the snapshot of a

running VM.





After selecting options and clicking “Run Backup”, the resultingarchives and their associated “info” files will be placed on the

SANmelody virtual volume and thus replicated via AIM to the DRcenter.

Active Data Replication

AUTOMATING THE BACKUP PROCESS

The vRanger Pro GUI facilitates creating CLI scripts. The selections

we make in the GUI result in command lines which can easily be putinto scripts and scheduled.

Copying the CLI Command to Build a Script

DataCore also provides scripting to drive its snapshot and AIM

commands. We can use the AIM Snapshot command after ourbackups have completed to insert an in-band snapshot request intothe data stream. In this way, once our backups have been replicated

to the DR site, a snapshot will be enabled or incremented. We can usethe snapshot to run a backup, or to set a coherency point should we

need to test or use the DR site.

The batch file will look something like this:

"C:\Program Files\vizioncore\esxRanger Professional\esxRangerProCli.exe"-virtualcenter vc2://Folder=group-d1 -copylocal V:\vRanger-drives:all -totalasync 10 -hostasync 2 -lunasync 3 –vmnotes-diffratio 50 -maxfullage 14 -retendays 31–zipname [config]_[year][month][day][hour][minute][second]-autodiff -mailonerror –vss

DCSAppRCmd -c \\tussmya "AIMSnapshot vRanger"





The last command instructs our TUSSMYA SANmelody server to send a

snapshot request to the AUSSMYB SANmelody server at the DR site inAustin following the transfer of the replicated backups.

USING THE REPLICATED BACKUPS

In the previous section we alluded to using snapshots at the DRfacility. Snapshots allow us to make a usable coherency point on our

AD-vRanger volume. This is advisable, because when our backupsoccur and the data is replicated to the DR site, the AD-vRanger volume

will be changing as the replicated writes are “de-staged” into their

corresponding locations.In SANmelody, snapshots are a relationship between a “source”

volume and a snapshot “destination” volume. SANmelody snapshots

use “Copy On First Write” technology, and when based on ThinProvisioned volumes, the snapshots are not storage-costly.

A Snapshot Relationship for the Daily Backup





TURNING ON THE DR SITE

To use the replicated volume at the DR site, we map a snapshot of the “AD-vRanger” volume from our AUSSMYB SANmelody server to the DR

site’s Virtual Center / vRanger server.

LUN Masking The Snapshot of AD-vRanger

We then discover the volume on the server with a “Rescan”. Opening

it, we find the vRanger Pro backup archives in tact, ready for use.

Mounted Snapshot of the Replicated Volume Ready For Use





RESTORING A REPLICATED VM

Although we have replicated our vRanger Pro archives, we’ve notreplicated the vRanger Pro database which lists all the available

archives. Obviously, the list of available archives will appear empty,as in the screenshot below. To restore our VM’s, we will use the

“Restore from Info” feature of vRanger Pro.

Restoring our VM’s by Browsing For Info Files





Selecting “Restore FromInfo” produces a dialog

with three screens. Ourfirst step is to browse for

our VM archives on the

AD-Ranger snapshotvolume. We select adifferential backup of

SQL01.

After selecting the VMs wewish to restore, we navigate

to the second screen wherewe select the destination ESX

host and associated VMFSdatastore.

Navigating to the thirdscreen, we accept thedefault options, and

arbitrarily decide torename the restored VM

“DR-SQL01”.

As you can see, vRanger

Pro allows you to capturethe commands forscripting the restoration

process. If we arereplicating a large number

of VMs, this can facilitatebringing our DR site live.





Once the restore has completed, we successfully power on the VMs atthe DR site. The ESX server will notice that the machine files have

been moved and will recommend we create a new Unique Identifier(UUID). Selecting “Create”, we dismiss the dialog.





The VM boots up. We’re prepared… ready for a disaster.

Console of a Replicated VM at the DR Site

THE OFFSITE BACKUP

A business can spend a small fortune in backup services, transportingtapes offsite to a “secure” facility. Alas, if those tapes were hijackeden route and their contents have not been encrypted, the resulting

situation can be as big a disaster as the one we’re developing our DRsite for. We might be better off using our replicated volumes to

implement the offsite backups at our presumably secure DR site.

If the data connection between the two sites is secure, we won’t have

to worry about encryption. Nonetheless, as we have seen, vRangerPro offers a data encryption feature.

Given the rash of recent incidents suffered by the large backup

services companies and their customers, our vRanger / AIM internethighway solution clearly offers a more secure means of getting ourbackups offsite than using the traditional asphalt highway approach.

Once the vRanger backup files are at the DR site, we in effect have our “offsite backup”. However, we have several options for what we do



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with those files. Clearly, we can present a snapshot of the replicatedvRanger volume to our backup server and run a traditional backup to a

tape library at the DR facilty. Additionally – or alternatively – we cansimply use SANmelody’s Complete Image Snapshot to make a clone of

the snapshot onto a physically separate set of disks – in effect, a disk-

to-disk backup.

CONCLUSION

SANmelody and vRanger Pro products each offer powerful solutions

for the datacenter. SANmelody is an outstanding software solution forimplementing full-featured SANs and allows IT professionals to custom

build their storage infrastructure according to their needs. vRangerPRO is the essential backup / restore tool for virtual server

environments.

Bringing the two products together in an integrated DR / backup and

offsite backup solution provides an elegant, reliable and cost effectivemeans for businesses to protect their data and keep their applications

available.

Documents

VizioncoreDatacore Whitepaper