Whitepaper: Continuous Data Protection on ReadyNAS

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Pointer-based snapshots are an eective data protection solution for the following reasons:
 • Highlevelofdataprotection,recoverabilityandavailabilitywhilemaximizingsystemup-time
 • Automateddataprotectionwithnoperformanceimpactorcapacitywastewhileapplicationsarerunning
 • Zerodataloss,theabilitytomeetrecoverypointobjectives(RPOs)andcontinuousdataprotectionwithout
negatively impacting performance
 • Fastrecoverability
As with any great idea, true snapshots also have their imitators. It is important that users not be fooled by limited snapshot
solutions that aren’t pointer-based. When a vendor advertises a limited number of snapshots (usually less than 100), that
means the underlying snapshot technology is a legacy copy-on-write snapshot (COW). The drawback of COW technology
is that it impacts the performance as soon as it’s enabled. These snapshots are impractical in a modern storage solution as
the more COW snapshots you have, the slower your system can perform.
True pointer-based snapshots are instant, only use incremental space and require no performance overhead. Only by
combining these three qualities can snapshots truly provide automated granular protection (e.g. hourly). This technology
allows users and administrators to access any data from the past without a performance cost to production storage and
wait time for recovery.
What is the dierence between a Pointer-based snapshot, COW snapshot and
traditional backup (copy)?
Pointer Snapshots COW Snapshots Legacy Backup (copy)
Space eciency High High Poor
Time-to-create Instant Instant Slow and dependent on change
Performance impact None High Medium
Number of snapshots/backups Unlimited Limited by performance Limited by capacity
Frequency of protection Hourly, Daily, weekly, monthly Temporary and infrequent Hourly, Daily, weekly, monthly
ReadyNASOS6solutionshavebuilt-inpointer-basedsnapshots.OurLinux-basedcompetitorsthatclaimsnapshot
support can only provide COW snapshots or legacy backup (copies). For this reason only NETGEAR provides unlimited,
granular protection of your production data at scale that is aordable for the SMB or home user.
Cloned snapshots (Writable) – Instant DR testing and recovery
Pointer-based hourly snapshots are great for retrieving individual files that may have been deleted or corrupted accidently
atanypointintime.Workingwithlargerdatafromasvirtualmachinesisslightlymorecomplex.Beingabletopullalarge
(forexample1TB)VMfromapointer-basedsnapshot(readonly)isnice.However,pullingmassivelesoutofasnapshot
can be time consuming. Wouldn’t it be nice to power on that VM directly from within the snapshot without a need to move
any data? ReadyNAS OS 6 allows administrators to create an instant writable clone to do just that.
Not only can you retrieve data from within a snapshot but you can also be using accessing the data while it continues to
residewithinthesnapshot.InthecaseofVirtualMachines(VMware,Hyper-VorCitrixXen)youcanpoweronaVMfrom
any previous snapshot without any wait time. This is an ideal solution for quick disaster recovery or even non-impact
disaster recovery testing.