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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.


ITS Datacentres

We run primary copy backup servers in the Chemistry / ITS central campus data centre. There are no production servers in this location. Backup data is also copied over the network to other data centres around campus so that it is accessible should we have issues with our main facility.

Our data centres are:

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




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

We have dedicated 40Gbit connectivity to the campus network.



HP DL380p Servers

Eleven '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.



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 equivilent)
    • 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 2015. The Green highlighted days show the restore points avalible.


As you go back in time, the restore points get further apart. To restore a file, it must have existed during one of the backup events. For example, If you created a file on 21 Dec 2014 and deleted it on the 24th Dec 2014, it would not be avalible to recover as only the monthly backup is kept that far back.

Cost Comparison (Feb 2015)

There are several options avalible to manage 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 £75
Snapshot / Previous Versions
  • Simple to manage.
  • Instant restores.
  • All users have 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.
  • Requires dedicated hardware and software.
? £1778
Cloud Backup              

Acronis server backup

  • Fixed monthly/yearly cost.
  • Outsourced software & hardware.
  • No control over data once in cloud.
  • Slow recovery time.
  • Assumes internet bandwidth is free.
? £795
EMC Mozy £2949
ITS Backup Service
  • Fully managed enterprise grade solution for a fixed yearly cost.
  • Lower costs due to economies of scale.
  • Unsuitable for niche applications.
32 £150