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Backup FAQs & Additional Information

More information about the service:

The Hardware

Data Retention

Cost Comparison


The Hardware

Here an overview of the current hardware used in our Commvault system.

Image shows an aisle inside our data centre.  A central white walkway is lit by spotlights overhead, each side is a line of back cabinets containing the servers we run.

ITS Datacentres

Backup data from your servers is sent to a dedicated backup location on campus. Once backups have completed, the data is then replicated to other data centres around campus. Your data is available for recovery from any of these locations.

Our data centres are:

  • Physically secure, access is controlled & recorded via staff ID cards.
  • Covered by CCTV
  • Air-conditioned
  • UPS Protected from powercuts & brownouts


A stack of green rack mounted network switches, some containing 24, others 48 ports. Made by Cisco, similar to those used in our data centre.


We can perform backups over the standard campus network. If required, a dedicated backup VLAN is avalible in ITS data centres.

Our dedicated backup location has 40Gbit connectivity to the campus network, each Commvault server has multiple 10Gbit connections to its local network.


A HP DL380P rack mounted server

HP DL380p Servers

'Media agent' servers receive and process backup data from clients. Five of these are located in remote data centres to manage the secondary copies.

  • Dual power supplies
  • Multiple 10Gbit Ethernet connections aggregated.
  • SSDs for system partitions with hot spare.
  • 4x 1TB SSD for index cache with spare.
  • 4x 1.6TB intel PCIe NVMe SSD for dedupe databases.


A rack mounted disk storage array.  Containing 90 3.5

Storage Arrays

Nine storage arrays (5.5PB usable) located across the campus data centres.

  • Custom build NAS systems. BSD & ZFS based.
  • Dual 8 Core Intel XEON CPU, 196GB RAM, SSD boot drives. Dual 10Gbit Ethernet.
  • 90 Disk JBOD:
    • 9x 10 SAS3 disk (8TB or 12TB) arrays
    • RAID Z2 (RAID 6 equivalent)
    • 2x hot spare drives
    • Dual 12Gbit SAS interconnect
    • Quad power supplies
    • Dual Expander
  • Capable of 4GB/sec raw IO internally (scrubs etc), 1.5GB/sec real world.



Backup Retention

Backups are retained depending on the service you choose, however the retention concept remains the same.

Here is an example of the restore points, for a server on the 'Standard Backup' product.

› 14 Daily Backups
› 4 End-of-week backups
› 12 End-of-month backups
› 2 End-of-year backups

This example assumes today is the 2nd of April. The Green highlighted days show the restore points available if a request to restore data was recieved on the 2nd of April.

Two year calendar image showing the recovery points available at a given date.  In the calendar, the days where recovery points are available are highlighted in green.  The available recovery points are described above.

As you go back further in time, the restore points get further apart. Files can only be restored if they existed at the time the backup was made. For example, If you created a file on 21 Dec and deleted it on the 24th Dec in the previous year, it would not be available for recovery.

Cost Comparison

There are several options available to manage the risk of data loss. Here are are some valid options, priced per TB per year.

Option Benefits Drawbacks Restore Points Hardware Failure Software Failure User Error Additional Cost
per TB / Year
Do Nothing
  • Appropriate where data
    has no business value.
  • No data protection
0 £0
Mirror Data
  • Simple to manage.
  • Hot standby is possible.
  • Limited protection. Data corruption on primary is mirrored to secondary.
1 £35
Snapshot / Previous Versions
  • Simple to manage.
  • Instant restores.
  • All users have the ability to restore ENTIRE volume to previous state.
  • Large changes of data or deletion may not be recoverable.
? £13

Barracuda backup appliance 290

  • Custom product configured to exact requirements.
  • Ideal for niche applications.
  • Requires resource to implement, administer & maintain.
  • £ Cost
? £1776
Cloud Backup              

Acronis server backup & 1TB Cloud storage

  • Fixed monthly/yearly cost.
  • Outsourced software & hardware.
  • No control over data once in cloud.
  • Slow recovery time.
  • Assumes internet bandwidth is free.
? £1400
ITS Backup Service
  • Fully managed enterprise-grade solution for a fixed yearly cost.
  • Lower costs due to economies of scale.
  • Unsuitable for niche applications.
26+ £150


  • 5 year hardware refresh cycle.
  • Primary storage cost at £35TB/Year (High Capacity Filestore Service)
  • Restores points '?' where they can vary depending on config or available space.