Redundancy & Backup Concepts

Hard Drive Redundancy Scenarios

We have come across many business owners who are constantly pondering weather or not they need some sort of backup solution for their data. They ask us, “Why do I need a local back up?” Or “Why should I have a local backup and a cloud solution?” Backup concepts are sometimes falsely conceived, so thanks to our Technical Operations Manager, Geoff Brady, you can now use this webpage as a reference in understanding Redundancy & Backup Concepts.

Backup Concepts

  • Pros: Affordable, Easy to manage
    Cons: Single Point of Failure; No redundancy
    Comments: Typically found in PC s
    Failure Risk: If the single drive fails, the system is offline; data integrity may be compromised
  • Pros: Affordable, Expandable Drive Space Easy to manage
    Cons: Single Point of Failure; No redundancy Comments: Uses RAID Control Card to make Windows think there is only one drive
    Failure Risk: If one of the drives fail, the system is offline; data integrity may be compromised
  • Pros: Cost-effective solution for a good level of drive redundancy Cons: Expansion is limited
    Comments: Uses a RAID Control Card to mirror data from one drive to another. Windows sees one hard drive, not two
    Failure Risk: If one of the drives fail, the system will switch to the mirror backup and continue operation
  • Pros: More Expensive, but excellent redundancy for the cost; expandable storage for server growth
    Cons: Cost for third drive, slightly more complex setup
    Comments: A RAID 5 essentially writes a little bit of the file to each drive. Windows sees one hard drive, not three
    Failure Risk: If the a single drive fails, the system will continue to operate uninterrupted
  • Redundancy & Backup Concepts
  • Pros: Affordable, Software included in windows
    Cons: Reloading of operating system necessary
    Time to restore: Moderate

    Pros: Local image provides complete system and file recover; can be virtualized if necessary
    Cons: Requires 3rd party software
    Time to restore: Fast

    Pros: Offsite backup; Time retention (e.g. 30 days)
    Cons: Restore needs download or data shipped to site from vendor; Reload of OS.
    SQL and Email require special backup software
    Time to restore: Slow

More Info

While there are many products that perform backup operations, the process to the left are the three main methods; Local file and system state; snapshot (VSS), offsite (cloud) backup.

The important concept here is to have an over multi-faceted approach to a disaster recovery. Typically, an organization would engage in not only hardware redundancy,but two backup plans; a local and off-site.

The important concept here is to have an over multi-faceted approach to a disaster recovery. Typically, an organization would engage in not only hardware redundancy, but two backup plans; a local and off-site.

Time definitions:
Slow: 10-15 technical hours; 3-5 days business days
Moderate: 6-10 technical hours; 2-3 business days
Fast: 3-5 technical hours; 1-2 business days
Time does not include resolving hardware failures.